Resins that yield low haze films and the process for their production

ABSTRACT

Catalyst compositions comprising a first metallocene compound, a second metallocene compound, a third metallocene compound, a chemically-treated solid oxide, and an organoaluminum compound are provided. Methods for preparing and using the catalyst and polyolefins are also provided. The compositions and methods disclosed herein provide ethylene polymers having decreased haze while minimizing impact on other properties, such as dart impact.

TECHNICAL FIELD OF THE INVENTION

This invention relates to the field of olefin polymerization catalysis,catalyst compositions, methods for the polymerization andcopolymerization of olefins, polyolefins, and film resins, particularlyusing a supported catalyst composition.

BACKGROUND OF THE INVENTION

There exists a constant search to develop new olefin polymerizationcatalysts, catalyst activation processes, and methods of making andusing catalysts that will provide enhanced catalytic activities andpolymeric materials tailored to specific end uses.

One type of catalyst system utilizes metallocene compounds, which haveshown promise in tailoring polymer properties. However, there aresignificant challenges in developing catalysts that can providecustom-made polymers with a specific set of desired properties. It is ofinterest to develop metallocene-based catalytic systems that can beactivated with activating agents that do not require relativelyexpensive methylaluminoxane, yet still provide relatively highpolymerization activities.

Resins produced using metallocene catalysts have captured a significantportion of the linear low density polyethylene (LLDPE) market. Suchresins are characterized by a high dart impact. However, some LLDPEfilms do not exhibit the high clarity and low haze that are required, orat least desired, for many applications. As such, there remains a needfor a means to produce LLDPE resins using metallocene catalyst systemsthat result in films having high clarity and low haze, withoutsacrificing other properties, such as dart impact strength.

SUMMARY OF THE INVENTION

The present invention generally relates to new catalyst compositions andmethods of using such catalyst compositions to form polyolefins having alow haze and a high dart impact. The catalyst composition includes atleast a first metallocene, a second metallocene, and a third metallocenecompound, at least one of which forms polyolefins having at least somelong chain branching. The metallocenes are combined with a solidactivator, an aluminum alkyl compound, and an olefin monomer to producethe desired low haze polyolefin.

According to one aspect of the present invention, a catalyst compositioncomprises a first metallocene compound, a second metallocene compound, athird metallocene compound, a chemically-treated solid oxide, and anorganoaluminum compound. The first metallocene compound and the secondmetallocene compound are different from each other and have the formula:(RCpR′)₂(X¹)(X²)M¹;wherein each R is an aliphatic group having from about 3 to about 10carbon atoms, each R′ independently is H or an aliphatic group having upto 2 carbon atoms, (X¹) and (X²) independently are a halide, and M¹ isZr or Hf.

The third metallocene compound has the formula:(Cp)₂(X³)(X⁴)M²;  1)wherein (X³) and (X⁴) independently are a halide, and M² is Zr or Hf; or(X⁵)(X⁶)(X⁷)(X⁸)M³;  2)wherein (X⁵) and (X⁶) independently are a cyclopentadienyl or an indenylgroup, and (X⁵) and (X⁶) are connected by a methylene, an ethylene, or adimethyl silicon bridging group. (X⁷) and (X⁸) independently are ahalide, and M³ is Zr or Hf.

According to this and other aspects of the present invention, thechemically-treated solid oxide comprises a solid oxide treated with anelectron-withdrawing anion. Chemically-treated solid oxides that may besuitable for use with the present invention include, but are not limitedto, fluorided alumina, chlorided alumina, bromided alumina, sulfatedalumina, fluorided silica-alumina, chlorided silica-alumina, bromidedsilica-alumina, sulfated silica-alumina, fluorided silica-zirconia,chlorided silica-zirconia, bromided silica-zirconia, sulfatedsilica-zirconia, triflated silica-alumina, silica treated with afluoroborate, or any combination thereof.

Examples of organoaluminum compounds that may be used with this andvarious other aspects of the present invention have the formula:Al(X⁹)_(n)(X¹⁰)_(3−n);wherein (X⁹) is a hydrocarbyl having from 1 to about 20 carbon atoms,(X¹⁰) is an alkoxide or an aryloxide having from 1 to about 20 carbonatoms, a halide, or a hydride, and n is a number from 1 to 3, inclusive.

According to another aspect of the present invention, a catalystcomposition comprises bis(n-butylcyclopentadienyl)dichlorozirconium,bis(1,3-butylmethylcyclopentadienyl)dichlorozirconium, a thirdmetallocene compound, at least one chemically-treated solid oxide, andat least one organoaluminum compound. The third metallocene compound hasthe formula:(Cp)₂(X³)(X⁴)M²;  1)wherein (X³) and (X⁴) independently are a halide, and M² is Zr or Hf; or(X⁵)(X⁶)(X⁷)(X⁸)M³;  2)wherein (X⁵) and (X⁶) independently are a cyclopentadienyl or an indenylgroup, and (X⁵) and (X⁶) are connected by an ethylene bridging group.(X⁷) and (X⁸) independently are a halide, and M³ is Zr or Hf.

One example of a catalyst composition formed according to the presentinvention comprises the contact product ofbis(n-butylcyclopentadienyl)dichlorozirconium,bis(1,3-butylmethylcycloentadienyl)dichlorozirconium,bis(cyclopentadienyl)dichlorozirconium, a chemically-treated solidoxide, and an organoaluminum compound.

Another example of a catalyst composition formed according to thepresent invention comprises the contact product ofbis(n-butylcyclopentadienyl)dichlorozirconium,bis(1,3-butylmethylcycloentadienyl)dichlorozirconium,1,2-ethylenebis(1-indenyl)dichlorozirconium, a chemically-treated solidoxide, and an organoaluminum compound.

According to another aspect of the present invention, a process forproducing a catalyst composition comprises contacting a firstmetallocene compound, a second metallocene compound, a third metallocenecompound, a chemically-treated solid oxide, and an organoaluminumcompound. The first metallocene compound and the second metallocenecompound are different from each other and have the formula:(RCpR′)₂(X¹)(X²)M¹;wherein each R is an aliphatic group having from about 3 to about 10carbon atoms, each R′ independently is H or an aliphatic group having upto 2 carbon atoms, (X¹) and (X²) independently are a halide, and M¹ isZr or Hf.

The third metallocene compound has the formula:(Cp)₂(X³)(X⁴)M²;  1)wherein (X³) and (X⁴) independently are a halide, and M² is Zr or Hf; or(X⁵)(X⁶)(X⁷)(X⁸)M³;  2)wherein (X⁵) and (X⁶) independently are a cyclopentadienyl or an indenylgroup, and (X⁵) and (X⁶) are connected by a methylene, an ethylene, or adimethyl silicon bridging group. (X⁷) and (X⁸) independently are ahalide, and M³ is Zr or Hf.

The present invention also encompasses a method of forming an olefinpolymer having a Carreau-Yasuda a value of from about 0.35 to about0.70, a recoverable shear parameter of from about 0.004 to about 0.080,and a film haze of less than about 25%. The method comprises contactinga catalyst composition with at least one type of olefin monomer. Thecatalyst composition comprises a first metallocene compound, a secondmetallocene compound, a third metallocene compound, a chemically-treatedsolid oxide, and an organoaluminum compound.

The present invention further encompasses a method of forming an olefinpolymer having a haze of less than about 10 percent. The methodcomprises contacting a catalyst composition with at least one type ofolefin monomer. The catalyst composition comprisesbis(n-butylcyclopentadienyl)dichlorozirconium,bis(1,3-butylmethylcycloentadienyl)dichlorozirconium,bis(cyclopentadienyl)dichlorozirconium, a chemically-treated solidoxide, and an organoaluminum compound.

The present invention still further encompasses a method of forming anolefin polymer having a haze of less than about 15 percent. The methodcomprises contacting a catalyst composition with at least one type ofolefin monomer. The catalyst composition comprisesbis(n-butylcyclopentadienyl)dichlorozirconium,bis(1,3-butylmethylcycloentadienyl)dichlorozirconium, and1,2-ethylenebis(1-indenyl)dichlorozirconium, a chemically-treated solidoxide, and an organoaluminum compound.

DEFINITIONS

To more clearly define the terms used herein, the following definitionsare provided. To the extent that any definition or usage provided by anydocument incorporated herein by reference conflicts with the definitionor usage provided herein, the definition or usage provided hereincontrols.

The term “polymer” is used herein to mean homopolymers comprisingethylene and copolymers of ethylene and at least one other olefiniccomonomer. “Polymer” is also used herein to mean homopolymers andcopolymers of any other polymerizable monomer disclosed herein.

The term “cocatalyst” is used generally herein to refer to theorganoaluminum compounds that may constitute one component of thecatalyst composition. Additionally, “cocatalyst” refers to the optionalcomponents of the catalyst composition including, but not limited to,aluminoxanes, organoboron compounds, organozinc compounds, or ionizingionic compounds, as disclosed herein. The term “cocatalyst” may be usedregardless of the actual function of the compound or any chemicalmechanism by which the compound may operate. In one aspect of thisinvention, the term “cocatalyst” is used to distinguish that componentof the catalyst composition from the metallocene compound.

The term “fluoroorgano boron compound” is used herein with its ordinarymeaning to refer to neutral compounds of the form BY₃. The term“fluoroorgano borate compound” also has its usual meaning to refer tothe monoanionic salts of a fluoroorgano boron compound of the form[cation]⁺[BY₄]⁻, where Y represents a fluorinated organic group. Forconvenience, fluoroorgano boron and fluoroorgano borate compounds aretypically referred to collectively as “organoboron compounds”, or byeither name as the context requires.

The term “precontacted” mixture is used herein to describe a firstmixture of catalyst components that are contacted for a first period oftime prior to the first mixture being used to form a “postcontacted” orsecond mixture of catalyst components that are contacted for a secondperiod of time. Typically, the precontacted mixture describes a mixtureof metallocene compound (or compounds), olefin monomer, andorganoaluminum compound (or compounds), before this mixture is contactedwith the activator-support and optional additional organoaluminumcompound. Thus, precontacted describes components that are used tocontact each other, but prior to contacting the components in thesecond, postcontacted mixture. Accordingly, this invention mayoccasionally distinguish between a component used to prepare theprecontacted mixture and that component after the mixture has beenprepared. For example, according to this description, it is possible forthe precontacted organoaluminum compound, once it is contacted with themetallocene and the olefin monomer, to have reacted to form at least onedifferent chemical compound, formulation, or structure from the distinctorganoaluminum compound used to prepare the precontacted mixture. Inthis case, the precontacted organoaluminum compound or component isdescribed as comprising an organoaluminum compound that was used toprepare the precontacted mixture.

Similarly, the term “postcontacted” mixture is used herein to describe asecond mixture of catalyst components that are contacted for a secondperiod of time, and one constituent of which is the “precontacted” orfirst mixture of catalyst components that were contacted for a firstperiod of time. Typically, the term “postcontacted” mixture is usedherein to describe the mixture of the metallocene compound, olefinmonomer, organoaluminum compound, and chemically-treated solid oxide,formed from contacting the precontacted mixture of a portion of thesecomponents with any additional components added to make up thepostcontacted mixture. Generally, the additional component added to makeup the postcontacted mixture is the chemically-treated solid oxide, and,optionally, may include an organoaluminum compound the same or differentfrom the organoaluminum compound used to prepare the precontactedmixture, as described herein. Accordingly, this invention may alsooccasionally distinguish between a component used to prepare thepostcontacted mixture and that component after the mixture has beenprepared.

The term “metallocene”, as used herein, describes a compound comprisingtwo η⁵-cycloalkadienyl-type ligands in the molecule. Thus, themetallocenes of this invention are bis(η⁵-cyclopentadienyl-type ligand)compounds, wherein the η⁵-cycloalkadienyl portions includecyclopentadienyl ligands, indenyl ligands, fluorenyl ligands, and thelike, including partially saturated or substituted derivatives oranalogs of any of these. Possible substituents on these ligands includehydrogen, therefore the description “substituted derivatives thereof” inthis invention comprises partially saturated ligands such astetrahydroindenyl, tetrahydrofluorenyl, octahydrofluorenyl, partiallysaturated indenyl, partially saturated fluorenyl, substituted partiallysaturated indenyl, substituted partially saturated fluorenyl, and thelike. In some contexts, the metallocene is referred to simply as the“catalyst”, in much the same way the term “cocatalyst” is used herein torefer to the organoaluminum compound. Unless otherwise specified, thefollowing abbreviations are used: Cp for cyclopentadienyl; Ind forindenyl; and Flu for fluorenyl.

The terms “catalyst composition”, “catalyst mixture”, and the like donot depend upon the actual product resulting from the contact orreaction of the components of the mixtures, the nature of the activecatalytic site, or the fate of the aluminum cocatalyst, the metallocenecompound, any olefin monomer used to prepare a precontacted mixture, orthe chemically-treated solid oxide after combining these components.Therefore, the terms “catalyst composition”, “catalyst mixture”, and thelike may include both heterogeneous compositions and homogenouscompositions.

The term “hydrocarbyl” is used herein to specify a hydrocarbon radicalgroup that includes, but is not limited to aryl, alkyl, cycloalkyl,alkenyl, cycloalkenyl, cycloalkadienyl, alkynyl, aralkyl, aralkenyl,aralkynyl, and the like, and includes all substituted, unsubstituted,branched, linear, heteroatom substituted derivatives thereof.

The terms “chemically-treated solid oxide”, “solid oxideactivator-support”, “acidic activator-support”, “activator-support”,“treated solid oxide compound”, or simply “activator”, and the like areused herein to indicate a solid, inorganic oxide of relatively highporosity, which exhibits Lewis acidic or Brønsted acidic behavior, andwhich has been treated with an electron-withdrawing component, typicallyan anion, and which is calcined. The electron-withdrawing component istypically an electron-withdrawing anion source compound. Thus, thechemically-treated solid oxide compound comprises the calcined contactproduct of at least one solid oxide compound with at least oneelectron-withdrawing anion source compound. Typically, thechemically-treated solid oxide comprises at least one ionizing, acidicsolid oxide compound. The terms “support” and “activator-support” arenot used to imply these components are inert, and such components shouldnot be construed as an inert component of the catalyst composition.

Although any methods, devices, and materials similar or equivalent tothose described herein can be used in the practice or testing of theinvention, the typical methods, devices and materials are hereindescribed.

All publications and patents mentioned herein are incorporated herein byreference for the purpose of describing and disclosing, for example, theconstructs and methodologies that are described in the publications,which might be used in connection with the presently describedinvention. The publications discussed above and throughout the text areprovided solely for their disclosure prior to the filing date of thepresent application. Nothing herein is to be construed as an admissionthat the inventors are not entitled to antedate such disclosure byvirtue of prior invention.

For any particular compound disclosed herein, any general structurepresented also encompasses all conformational isomers, regioisomers, andstereoisomers that may arise from a particular set of substituents. Thegeneral structure also encompasses all enantiomers, diastereomers, andother optical isomers whether in enantiomeric or racemic forms, as wellas mixtures of stereoisomers, as the context requires.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed generally to new catalystcompositions, methods for preparing catalyst compositions, methods forusing the catalyst compositions to polymerize olefins. In particular,the present invention relates to new catalyst compositions and methodsof using such catalyst compositions to form polyolefins having a lowhaze and a high dart impact. The catalyst composition includes at leastthree metallocenes, at least one of which forms a polyolefin having atleast some long chain branching. The metallocenes are combined with asolid activator, an aluminum alkyl compound, and an olefin monomer toproduce the desired low haze polyolefin. It has been discovered that thetri-metallocene catalyst system of the present invention provides auseful combination of polyolefin properties, such as melt index, haze,MD tear, and the like, while maintaining sufficient melt strength so theresin is suitable for blowing film.

According to one aspect of the present invention, a composition ofmatter is provided. The composition includes a first metallocenecompound, a second metallocene compound, a third metallocene compound, achemically-treated solid oxide, and an organoaluminum compound.According to other aspects, the present invention is directed to acatalyst composition, a catalyst composition for polymerizing olefins, amethod of preparing a catalyst composition, a method of using a catalystcomposition, and the like, in each case encompassing a first metallocenecompound, a second metallocene compound, a third metallocene compound, achemically-treated solid oxide, and an organoaluminum compound.According to another aspect of the present invention, a method forproducing polyolefins and films is provided.

A. Catalyst Composition and Components

The present invention is directed to a catalyst composition including afirst metallocene compound, a second metallocene compound, a thirdmetallocene compound, a chemically-treated solid oxide, and anorganoaluminum compound. At least one of the metallocene compoundsproduces long chain branching in a polyolefin. The combination ofmetallocenes is used with a chemically-treated solid oxide and anorganolaluminum compound to form polyolefins having low haze. Otherphysical characteristics, such as dart impact, are not adverselyaffected.

1. The Metallocene Compounds

(a) The First Metallocene Compound

According to one aspect of the present invention, the first metallocenecompound has the formula:(RCpR′)₂(X¹)(X²)M¹;

wherein each R is an aliphatic group having from about 3 to about 10carbon atoms, each R′ independently is H or an aliphatic group having upto 2 carbon atoms, (X¹) and (X²) independently are a halide, and M¹ isZr or Hf. In this and other aspects of the present invention, R may ben-butyl. In this and other aspects of the present invention, R′ may beethyl. In this and other aspects, (X¹) and (X²) may be the same ordifferent.

According to another aspect of the present invention, the firstmetallocene compound has the formula:(RCpR′)₂(X¹)(X²)M¹;wherein each R is a linear aliphatic group having from about 3 to about10 carbon atoms, each R′ independently is selected from H or a linearaliphatic group having up to 2 carbon atoms, (X¹) and (X²) independentlyare a halide, and M¹ is Zr or Hf.

Examples of metallocene compounds that may be suitable for use as thefirst metallocene compound in accordance with the present inventioninclude, but are not limited to,bis(n-butylcyclopentadienyl)dichlorozirconium:

bis(n-butylcyclopentadienyl)dichlorohafnium:

a combination thereof.

(b) The Second Metallocene Compound

According to one aspect of the present invention, the second metallocenecompound has the formula:(RCpR′)₂(X¹)(X²)M¹;wherein each R is an aliphatic group having from about 3 to about 10carbon atoms, each R′ independently is H or an aliphatic group having upto 2 carbon atoms, (X¹) and (X²) independently are a halide, and M¹ isZr or Hf. In this and other aspects of the present invention, R may ben-butyl. In this and other aspects of the present invention, R′ may beethyl. In this and other aspects, (X¹) and (X²) may be the same ordifferent.

According to another aspect of the present invention, the secondmetallocene compound has the formula:(RCpR′)₂(X¹)(X²)M¹;wherein each R is a linear aliphatic group having from about 3 to about10 carbon atoms, each R′ independently is selected from H or a linearaliphatic group having up to 2 carbon atoms, (X¹) and (X²) independentlyare a halide, and M¹ is Zr or Hf.

Examples of metallocene compounds that may be suitable for use as thesecond metallocene compound in accordance with the present inventioninclude, but are not limited to,bis(1,3-butylmethylcyclopentadienyl)dichlorozirconium:

bis(1,3-butylmethylcyclopentadienyl)dichlorohafnium:

or a combination thereof.

(c) The Third Metallocene Compound

According to one aspect of the present invention, the third metallocenecompound has the formula:(Cp)₂(X³)(X⁴)M²;  1)wherein (X³) and (X⁴) independently are a halide, and M² is Zr or Hf; or(X⁵)(X⁶)(X⁷)(X⁸)M³;  2)wherein (X⁵) and (X⁶) independently are a cyclopentadienyl or an indenylgroup, (X⁵) and (X⁶) are connected by a methylene, an ethylene, or adimethyl silicon bridging group, (X⁷) and (X⁸) independently are ahalide, and M³ is Zr or Hf. In this and other aspects, (X⁷) and (X⁸) maybe the same or different.

According to another aspect of the present invention, the thirdmetallocene compound has the formula:(Cp)₂(X³)(X⁴)M²;  1)wherein (X³) and (X⁴) independently are a halide, M² is Zr or Hf; or(X⁵)(X⁶)(X⁷)(X⁸)M³;  2)wherein (X⁵) and (X⁶) independently are a cyclopentadienyl or an indenylgroup, (X⁵) and (X⁶) are connected by an ethylene bridging group, (X⁷)and (X⁸) independently are a halide, M² is Zr or Hf, and M³ is Zr or Hf.

Examples of metallocene compounds that may be suitable for use as thethird metallocene compound in accordance with the present inventioninclude, but are not limited to, bis(cyclopentadienyl)dichlorozirconium:

bis(cyclopentadienyl)dichlorohafnium:

1,2-ethylenebis(1-indenyl)dichlorozirconium:

1,2-ethylenebis(1-indenyl)dichlorohafnium:

any combination thereof.

One example of a catalyst composition formed according to the presentinvention comprises bis(n-butylcyclopentadienyl)dichlorozirconium,bis(1,3-butylmethylcyclopentadienyl)dichlorozirconium,bis(cyclopentadienyl)dichlorozirconium, a chemically-treated solidoxide, and an organoaluminum compound. In any of the above compounds,zirconium may be substituted with hafnium.

Another example of a catalyst composition formed according to thepresent invention comprisesbis(n-butylcyclopentadienyl)dichlorozirconium,bis(1,3-butylmethylcyclopentadienyl)dichlorozirconium,1,2-ethylenebis(1-indenyl)dichlorozirconium, a chemically-treated solidoxide, and an organoaluminum compound. In any of the above compounds,zirconium may be substituted with hafnium.

Catalyst compositions including various combinations of thesemetallocenes including, but not limited to, at least one firstmetallocene compound, at least one second metallocene compound, at leastone third metallocene compound, and any combination of more than onefirst metallocene compound, more than one second metallocene compound,and more than one third metallocene compound are also contemplated bythis invention. Further, use of more than one chemically-treated solidoxide and more than one organoaluminum compound are also contemplated.

2. The Activator-Support

The present invention encompasses various catalyst compositionsincluding an activator-support comprising a chemically-treated solidoxide.

The chemically-treated solid oxide exhibits enhanced acidity as comparedto the corresponding untreated solid oxide compound. Thechemically-treated solid oxide also functions as a catalyst activator ascompared to the corresponding untreated solid oxide. While thechemically-treated solid oxide activates the metallocene in the absenceof cocatalysts, it is not necessary to eliminate cocatalysts from thecatalyst composition. The activation function of the activator-supportis evident in the enhanced activity of catalyst composition as a whole,as compared to a catalyst composition containing the correspondinguntreated solid oxide. However, it is believed that thechemically-treated solid oxide can function as an activator, even in theabsence of an organoaluminum compound, aluminoxanes, organoboroncompounds, or ionizing ionic compounds.

The chemically-treated solid oxide may comprise at least one solid oxidetreated with at least one electron-withdrawing anion. While notintending to be bound by the following statement, it is believed thattreatment of the solid oxide with an electron-withdrawing componentaugments or enhances the acidity of the oxide. Thus, theactivator-support exhibits Lewis or Brønsted acidity that is typicallygreater than the Lewis or Brønsted acid strength than the untreatedsolid oxide, or the activator-support has a greater number of acid sitesthan the untreated solid oxide, or both. One method to quantify theacidity of the chemically-treated and untreated solid oxide materials isby comparing the polymerization activities of the treated and untreatedoxides under acid catalyzed reactions.

The chemically-treated solid oxide of this invention is formed generallyfrom an inorganic solid oxide having a relatively high porosity thatexhibits Lewis acidic or Brønsted acidic behavior. The solid oxide ischemically-treated with an electron-withdrawing component, typically anelectron-withdrawing anion, to form an activator-support.

According to one aspect of the present invention, the solid oxide usedto prepare the chemically-treated solid oxide may have a pore volumegreater than about 0.1 cc/g. According to another aspect of the presentinvention, the solid oxide may have a pore volume greater than about 0.5cc/g. According to yet another aspect of the present invention, thesolid oxide may have a pore volume greater than about 1.0 cc/g.

According to another aspect of the present invention, the solid oxidemay have a surface area of from about 100 to about 1000 m²/g. Accordingto yet another aspect of the present invention, the solid oxide may havea surface area of from about 200 to about 800 m²/g. According to stillanother aspect of the present invention, the solid oxide may have asurface area of from about 250 to about 600 m²/g.

The chemically-treated solid oxide may comprise a solid inorganic oxidecomprising oxygen and at least one element selected from Group 2, 3, 4,5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 of the periodic table, orcomprising oxygen and at least one element selected from the lanthanideor actinide elements. (See: Hawley's Condensed Chemical Dictionary,11^(th) Ed., John Wiley & Sons; 1995; Cotton, F. A.; Wilkinson, G.;Murillo; C. A.; and Bochmann; M. Advanced Inorganic Chemistry, 6^(th)Ed., Wiley-Interscience, 1999.) For example, the inorganic oxide maycomprise oxygen and at least one element selected from Al, B, Be, Bi,Cd, Co, Cr, Cu, Fe, Ga, La, Mn, Mo, Ni, Sb, Si, Sn, Sr, Th, Ti, V, W, P,Y, Zn or Zr.

Suitable examples of solid oxide materials or compounds that can be usedto form the chemically-treated solid oxide include, but are not limitedto, Al₂O₃, B₂O₃, BeO, Bi₂O₃, CdO, Co₃O₄, Cr₂O₃, CuO, Fe₂O₃, Ga₂O₃,La₂O₃, Mn₂O₃, MoO₃, NiO, P₂O₅, Sb₂O₅, SiO₂, SnO₂, SrO, ThO₂, TiO₂, V₂O₅,WO₃, Y₂O₃, ZnO, ZrO₂, and the like, including mixed oxides thereof, andcombinations thereof. For example, the solid oxide may be silica,alumina, silica-alumina, aluminum phosphate, heteropolytungstates,titania, zirconia, magnesia, boria, zinc oxide, mixed oxides thereof, orany combination thereof.

The solid oxide of this invention encompasses oxide materials such asalumina, “mixed oxide” compounds thereof such as silica-alumina, andcombinations and mixtures thereof. The mixed oxide compounds such assilica-alumina can be single or multiple chemical phases with more thanone metal combined with oxygen to form a solid oxide compound. Examplesof mixed oxides that can be used in the activator-support of the presentinvention include, but are not limited to, silica-alumina,silica-titania, silica-zirconia, zeolites, various clay minerals,alumina-titania, alumina-zirconia, zinc-aluminate and the like.

The electron-withdrawing component used to treat the solid oxide may beany component that increases the Lewis or Brønsted acidity of the solidoxide upon treatment (as compared to the solid oxide that is not treatedwith at least one electron-withdrawing anion). According to one aspectof the present invention, the electron-withdrawing component is anelectron-withdrawing anion derived from a salt, an acid, or othercompound, such as a volatile organic compound, that may serve as asource or precursor for that anion. Examples of electron-withdrawinganions include, but are not limited to, sulfate, bisulfate, fluoride,chloride, bromide, iodide, fluorosulfate, fluoroborate, phosphate,fluorophosphate, trifluoroacetate, triflate, fluorozirconate,fluorotitanate, trifluoroacetate, triflate, and the like, includingmixtures and combinations thereof. In addition, other ionic or non-ioniccompounds that serve as sources for these electron-withdrawing anionsmay also be employed in the present invention.

Thus, for example, the chemically-treated solid oxide used with thepresent invention may be fluorided alumina, chlorided alumina, bromidedalumina, sulfated alumina, fluorided silica-alumina, chloridedsilica-alumina, bromided silica-alumina, sulfated silica-alumina,fluorided silica-zirconia, chlorided silica-zirconia, bromidedsilica-zirconia, sulfated silica-zirconia, triflated silica-alumina,silica treated with a fluoroborate, or any combination thereof.

When the electron-withdrawing component comprises a salt of anelectron-withdrawing anion, the counterion or cation of that salt may beselected from any cation that allows the salt to revert or decomposeback to the acid during calcining. Factors that dictate the suitabilityof the particular salt to serve as a source for the electron-withdrawinganion include, but are not limited to, the solubility of the salt in thedesired solvent, the lack of adverse reactivity of the cation,ion-pairing effects between the cation and anion, hygroscopic propertiesimparted to the salt by the cation, and the like, and thermal stabilityof the anion. Examples of suitable cations in the salt of theelectron-withdrawing anion include, but are not limited to, ammonium,trialkyl ammonium, tetraalkyl ammonium, tetraalkyl phosphonium, H⁺,[H(OEt₂)₂]⁺, and the like.

Further, combinations of one or more different electron-withdrawinganions, in varying proportions, can be used to tailor the specificacidity of the activator-support to the desired level. Combinations ofelectron-withdrawing components may be contacted with the oxide materialsimultaneously or individually, and in any order that affords thedesired chemically-treated solid oxide acidity. For example, one aspectof this invention is employing two or more electron-withdrawing anionsource compounds in two or more separate contacting steps.

Thus, one example of such a process by which a chemically-treated solidoxide is prepared is as follows: a selected solid oxide compound, orcombination of oxide compounds, is contacted with a firstelectron-withdrawing anion source compound to form a first mixture; thisfirst mixture is calcined and then contacted with a secondelectron-withdrawing anion source compound to form a second mixture; thesecond mixture is then calcined to form a treated solid oxide compound.In such a process, the first and second electron-withdrawing anionsource compounds may be different compounds or the same compound.

According to another aspect of the present invention, thechemically-treated solid oxide may comprise a solid inorganic oxidematerial, a mixed oxide material, or a combination of inorganic oxidematerials, that is chemically-treated with an electron-withdrawingcomponent, and optionally treated with a metal source, including metalsalts, metal ions, or other metal-containing compounds. The metal ormetal ion may be, for example, zinc, nickel, vanadium, titanium, silver,copper, gallium, tin, tungsten, molybdenum, or any combination thereof.Examples of chemically-treated solid oxides that include a metal ormetal ion include, but are not limited to, zinc-impregnated chloridedalumina, titanium-impregnated fluorided alumina, zinc-impregnatedfluorided alumina, zinc-impregnated chlorided silica-alumina,zinc-impregnated fluorided silica-alumina, zinc-impregnated sulfatedalumina, chlorided zinc aluminate, fluorided zinc aluminate, sulfatedzinc aluminate, or any combination thereof.

Any method of impregnating the solid oxide material with a metal may beused. The method by which the oxide is contacted with a metal source,typically a salt or metal-containing compound, may include, but is notlimited to, gelling, co-gelling, impregnation of one compound ontoanother, and the like. If desired, the metal-containing compound may beadded to or impregnated into the solid oxide in solution form, andsubsequently converted into the supported metal upon calcining.Accordingly, the solid inorganic oxide can further comprise a metalselected from zinc, titanium, nickel, vanadium, silver, copper, gallium,tin, tungsten, molybdenum, or a combination thereof. For example, zincmay be used to impregnate the solid oxide because it provides goodcatalyst activity and low cost.

The solid oxide may be treated with metal salts or metal-containingcompounds before, after, or at the same time that the solid oxide istreated with the electron-withdrawing anion. Following any contactingmethod, the contacted mixture of oxide compound, electron-withdrawinganion, and the metal ion is typically calcined. Alternatively, a solidoxide material, an electron-withdrawing anion source, and the metal saltor metal-containing compound are contacted and calcined simultaneously.

Various processes may be used to form the chemically-treated solidoxide. The chemically-treated solid oxide may comprise the contactproduct of at least one solid oxide compound and at least oneelectron-withdrawing anion source. It is not required that the solidoxide compound be calcined prior to contacting the electron-withdrawinganion source. The contact product may be calcined either during or afterthe solid oxide compound is contacted with the electron-withdrawinganion source. The solid oxide compound may be calcined or uncalcined.Various processes to prepare solid oxide activator-supports that can beemployed in this invention have been reported. For example, such methodsare described in U.S. Pat. Nos. 6,107,230, 6,165,929, 6,294,494,6,300,271, 6,316,553, 6,355,594, 6,376,415, 6,391,816, 6,395,666,6,524,987, and 6,548,441, each of which is incorporated by referenceherein in its entirety.

According to one aspect of the present invention, the solid oxidematerial may be chemically-treated by contacting it with at least oneelectron-withdrawing component, typically an electron-withdrawing anionsource. Further, the solid oxide material optionally may be chemicallytreated with a metal ion, and then calcined to form a metal-containingor metal-impregnated chemically-treated solid oxide. According toanother aspect of the present invention, the solid oxide material andelectron-withdrawing anion source are contacted and calcinedsimultaneously.

The method by which the oxide is contacted with the electron-withdrawingcomponent, typically a salt or an acid of an electron-withdrawing anion,may include, but is not limited to, gelling, co-gelling, impregnation ofone compound onto another, and the like. Thus, following any contactingmethod, the contacted mixture of the solid oxide, electron-withdrawinganion, and optional metal ion, is calcined.

The solid oxide activator-support (chemically-treated solid oxide) maythus be produced by a process comprising:

1) contacting a solid oxide compound with at least oneelectron-withdrawing anion source compound to form a first mixture; and

2) calcining the first mixture to form the solid oxideactivator-support.

According to another aspect of the present invention, the solid oxideactivator-support (chemically-treated solid oxide) may be produced by aprocess comprising:

1) contacting at least one solid oxide compound with a firstelectron-withdrawing anion source compound to form a first mixture;

2) calcining the first mixture to produce a calcined first mixture;

3) contacting the calcined first mixture with a secondelectron-withdrawing anion source compound to form a second mixture; and

4) calcining the second mixture to form the solid oxideactivator-support.

According to yet another aspect of the present invention, thechemically-treated solid oxide is produced or formed by contacting thesolid oxide with the electron-withdrawing anion source compound, wherethe solid oxide compound is calcined before, during, or after contactingthe electron-withdrawing anion source, and where there is a substantialabsence of aluminoxanes and organoborates.

Calcining of the treated solid oxide generally is conducted in anambient atmosphere, typically in a dry ambient atmosphere, at atemperature from about 200° C. to about 900° C., for about 1 minute toabout 100 hours. Calcining may be conducted at a temperature of fromabout 300° C. to about 800° C., for example, at a temperature of fromabout 400° C. to about 700° C. Calcining may be conducted for about 1hour to about 50 hours, for example, for about 3 hours to about 20hours. Thus, for example, calcining may be carried out for about 1 toabout 10 hours at a temperature of from about 350° C. to about 550° C.Any type of suitable ambient can be used during calcining. Generally,calcining is conducted in an oxidizing atmosphere, such as air.Alternatively, an inert atmosphere, such as nitrogen or argon, or areducing atmosphere, such as hydrogen or carbon monoxide, may be used.

According to one aspect of the present invention, the solid oxidematerial may be treated with a source of halide ion, sulfate ion, or acombination of anions, optionally treated with a metal ion, and thencalcined to provide the chemically-treated solid oxide in the form of aparticulate solid. For example, the solid oxide material may be treatedwith a source of sulfate (termed a “sulfating agent”), a source ofchloride ion (termed a “chloriding agent”), a source of fluoride ion(termed a “fluoriding agent”), or a combination thereof, and calcined toprovide the solid oxide activator. Useful acidic activator-supportsinclude, but are not limited to, bromided alumina, chlorided alumina,fluorided alumina, sulfated alumina, bromided silica-alumina, chloridedsilica-alumina, fluorided silica-alumina, sulfated silica-alumina,bromided silica-zirconia, chlorided silica-zirconia, fluoridedsilica-zirconia, sulfated silica-zirconia, triflated silica-alumina,silica treated with a fluoroborate; a pillared clay, such as a pillaredmontmorillonite, optionally treated with fluoride, chloride, or sulfate;phosphated alumina or other aluminophosphates optionally treated withsulfate, fluoride, or chloride; or any combination of the above.Further, any of the activator-supports may be optionally treated with ametal ion.

The chemically-treated solid oxide may comprise a fluorided solid oxidein the form of a particulate solid. The fluorided solid oxide may beformed by contacting a solid oxide with a fluoriding agent. The fluorideion may be added to the oxide by forming a slurry of the oxide in asuitable solvent such as alcohol or water including, but not limited to,the one to three carbon alcohols because of their volatility and lowsurface tension. Examples of fluoriding agents that may be suitableinclude, but are not limited to, hydrofluoric acid (HF), ammoniumfluoride (NH₄F), ammonium bifluoride (NH₄HF₂), ammoniumtetrafluoroborate (NH₄BF₄), ammonium silicofluoride (hexafluorosilicate)((NH₄)₂SiF₆), ammonium hexafluorophosphate (NH₄ PF₆), analogs thereof,and combinations thereof. For example, ammonium bifluoride (NH₄HF₂) maybe used as the fluoriding agent, due to its ease of use and readyavailability.

If desired, the solid oxide may be treated with a fluoriding agentduring the calcining step. Any fluoriding agent capable of thoroughlycontacting the solid oxide during the calcining step can be used. Forexample, in addition to those fluoriding agents described previously,volatile organic fluoriding agents may be used. Examples of volatileorganic fluoriding agents useful in this aspect of the inventioninclude, but are not limited to, freons, perfluorohexane,perfluorobenzene, fluoromethane, trifluoroethanol, and combinationsthereof. Gaseous hydrogen fluoride or fluorine itself also can be usedwhen the solid oxide is fluorided during calcining. One convenientmethod of contacting the solid oxide with the fluoriding agent is tovaporize a fluoriding agent into a gas stream used to fluidize the solidoxide during calcination.

Similarly, in another aspect of this invention, the chemically-treatedsolid oxide may comprise a chlorided solid oxide in the form of aparticulate solid. The chlorided solid oxide may be formed by contactinga solid oxide with a chloriding agent. The chloride ion may be added tothe oxide by forming a slurry of the oxide in a suitable solvent. Thesolid oxide may be treated with a chloriding agent during the calciningstep. Any chloriding agent capable of serving as a source of chlorideand thoroughly contacting the oxide during the calcining step may beused. For example, volatile organic chloriding agents may be used.Examples of volatile organic chloriding agents that may be suitableinclude, but are not limited to, certain freons, perchlorobenzene,chloromethane, dichloromethane, chloroform, carbon tetrachloride,trichloroethanol, or any combination thereof. Gaseous hydrogen chlorideor chlorine itself may also be used with the solid oxide duringcalcining. One convenient method of contacting the oxide with thechloriding agent is to vaporize a chloriding agent into a gas streamused to fluidize the solid oxide during calcination.

The amount of fluoride or chloride ion present before calcining thesolid oxide may be from about 2 to about 50% by weight, where weightpercent is based on the weight of the solid oxide, for example,silica-alumina, before calcining. According to another aspect of thisinvention, the amount of fluoride or chloride ion present beforecalcining the solid oxide may be from about 3 to about 25% by weight,and according to another aspect of this invention, may be from about 4to about 20% by weight. Once impregnated with halide, the halided oxidemay be dried by any method known in the art including, but not limitedto, suction filtration followed by evaporation, drying under vacuum,spray drying, and the like, although it is also possible to initiate thecalcining step immediately without drying the impregnated solid oxide.

The silica-alumina used to prepare the treated silica-alumina typicallyhas a pore volume greater than about 0.5 cc/g. According to one aspectof the present invention, the pore volume may be greater than about 0.8cc/g, and according to another aspect of the present invention, the porevolume may be greater than about 1.0 cc/g. Further, the silica-aluminamay have a surface area greater than about 100 m²/g. According to oneaspect of this invention, the surface area may be greater than about 250m²/g, and according to another aspect of this invention, the surfacearea may be greater than about 350 m²/g.

The silica-alumina used with this invention typically has an aluminacontent from about 5 to about 95%. According to one aspect of thisinvention, the alumina content of the silica-alumina may be from about 5to about 50%, and according to another aspect of this invention, thealumina content of the silica-alumina may be from about 8% to about 30%alumina by weight. According to yet another aspect of this invention,the solid oxide component may comprise alumina without silica, andaccording to another aspect of this invention, the solid oxide componentmay comprise silica without alumina.

The sulfated solid oxide comprises sulfate and a solid oxide component,such as alumina or silica-alumina, in the form of a particulate solid.Optionally, the sulfated oxide may be treated further with a metal ionsuch that the calcined sulfated oxide comprises a metal. According toone aspect of the present invention, the sulfated solid oxide comprisessulfate and alumina. In some instances, the sulfated alumina is formedby a process wherein the alumina is treated with a sulfate source, forexample, but not limited to, sulfuric acid or a sulfate salt such asammonium sulfate. This process may be performed by forming a slurry ofthe alumina in a suitable solvent, such as alcohol or water, in whichthe desired concentration of the sulfating agent has been added.Suitable organic solvents include, but are not limited to, the one tothree carbon alcohols because of their volatility and low surfacetension.

According to one aspect of this invention, the amount of sulfate ionpresent before calcining may be from about 0.5 parts by weight to about100 parts by weight sulfate ion to about 100 parts by weight solidoxide. According to another aspect of this invention, the amount ofsulfate ion present before calcining may be from about 1 part by weightto about 50 parts by weight sulfate ion to about 100 parts by weightsolid oxide, and according to still another aspect of this invention,from about 5 parts by weight to about 30 parts by weight sulfate ion toabout 100 parts by weight solid oxide. These weight ratios are based onthe weight of the solid oxide before calcining. Once impregnated withsulfate, the sulfated oxide may be dried by any method known in the artincluding, but not limited to, suction filtration followed byevaporation, drying under vacuum, spray drying, and the like, althoughit is also possible to initiate the calcining step immediately.

The activator-support used to prepare the catalyst compositions of thepresent invention may be combined with other inorganic supportmaterials, including, but not limited to, zeolites, inorganic oxides,phosphated inorganic oxides, and the like. In one aspect, typicalsupport materials that may be used include, but are not limited to,silica, silica-alumina, alumina, titania, zirconia, magnesia, boria,fluorided alumina, silated alumina, thoria, aluminophosphate, aluminumphosphate, phosphated silica, phosphated alumina, silica-titania,coprecipitated silica/titania, fluorided/silated alumina, and anycombination or mixture thereof.

According to yet another aspect of the present invention, one or more ofthe metallocene compounds may be precontacted with an olefin monomer andan organoaluminum compound for a first period of time prior tocontacting this mixture with the activator-support. Once theprecontacted mixture of the metallocene compound(s), olefin monomer, andorganoaluminum compound is contacted with the activator-support, thecomposition further comprising the activator-support is termed the“postcontacted” mixture. The postcontacted mixture may be allowed toremain in further contact for a second period of time prior to beingcharged into the reactor in which the polymerization process will becarried out.

3. The Organoaluminum Compound

Organoaluminum compounds that may be used with the present inventioninclude, but are not limited to, compounds having the formula:(R²)₃Al;

where (R²) is an aliphatic group having from 2 to about 6 carbon atoms.For example, (R²) may be ethyl, propyl, butyl, hexyl, or isobutyl.

Other organoaluminum compounds that may be used in accordance with thepresent invention include, but are not limited to, compounds having theformula:Al(X⁹)_(n)(X¹⁰)_(3−n),where (X⁹) is a hydrocarbyl having from 1 to about 20 carbon atoms,(X¹⁰) is an alkoxide or an aryloxide, any one of which having from 1 toabout 20 carbon atoms, a halide, or a hydride, and n is a number from 1to 3, inclusive. According to one aspect of the present invention, (X⁹)is an alkyl having from 1 to about 10 carbon atoms. Examples of (X⁹)moieties include, but are not limited to, ethyl, propyl, n-butyl,sec-butyl, isobutyl, hexyl, and the like. According to another aspect ofthe present invention, (X¹⁰) may be independently selected from fluoroor chloro. According to yet another aspect of the present invention,(X¹⁰) may be chloro. In the formula Al(X⁹)_(n)(X¹⁰)_(3−n), n is a numberfrom 1 to 3 inclusive, and typically, n is 3. The value of n is notrestricted to be an integer; therefore, this formula includessesquihalide compounds or other organoaluminum cluster compounds.

Examples of organoaluminum compounds that may be suitable for use withthe present invention include, but are not limited to, trialkylaluminumcompounds, dialkylaluminum halide compounds, dialkylaluminum alkoxidecompounds, dialkylaluminum hydride compounds, and combinations thereof.Specific examples of organoaluminum compounds that may be suitableinclude, but are not limited to: trimethylaluminum (TMA),triethylaluminum (TEA), tripropylaluminum, diethylaluminum ethoxide,tributylaluminum, diisobutylaluminum hydride, triisobutylaluminum, anddiethylaluminum chloride.

The present invention contemplates precontacting the first metallocenecompound, the second metallocene compound, or both, with at least oneorganoaluminum compound and an olefin monomer to form a precontactedmixture, prior to contacting this precontacted mixture with theactivator-support to form the active catalyst. When the catalystcomposition is prepared in this manner, typically, though notnecessarily, a portion of the organoaluminum compound is added to theprecontacted mixture and another portion of the organoaluminum compoundis added to the postcontacted mixture prepared when the precontactedmixture is contacted with the solid oxide activator. However, the entireorganoaluminum compound may be used to prepare the catalyst in eitherthe precontacting or postcontacting step. Alternatively, all thecatalyst components may be contacted in a single step.

Further, more than one organoaluminum compound may be used in either theprecontacting or the postcontacting step. When an organoaluminumcompound is added in multiple steps, the amounts of organoaluminumcompound disclosed herein include the total amount of organoaluminumcompound used in both the precontacted and postcontacted mixtures, andany additional organoaluminum compound added to the polymerizationreactor. Therefore, total amounts of organoaluminum compounds aredisclosed regardless of whether a single organoaluminum compound or morethan one organoaluminum compound is used.

4. The Optional Aluminoxane Cocatalyst

The present invention further provides a catalyst composition comprisingan optional aluminoxane cocatalyst. As used herein, the term“aluminoxane” refers to aluminoxane compounds, compositions, mixtures,or discrete species, regardless of how such aluminoxanes are prepared,formed, or otherwise provided. For example, a catalyst compositioncomprising an optional aluminoxane cocatalyst can be prepared in whichaluminoxane is provided as the poly(hydrocarbyl aluminum oxide), or inwhich aluminoxane is provided as the combination of an aluminum alkylcompound and a source of active protons such as water. Aluminoxanes arealso referred to as poly(hydrocarbyl aluminum oxides) ororganoaluminoxanes.

The other catalyst components typically are contacted with thealuminoxane in a saturated hydrocarbon compound solvent, though anysolvent that is substantially inert to the reactants, intermediates, andproducts of the activation step may be used. The catalyst compositionformed in this manner may be collected by methods known to those ofskill in the art including, but not limited to, filtration.Alternatively, the catalyst composition may be introduced into thepolymerization reactor without being isolated.

The aluminoxane compound of this invention may be an oligomeric aluminumcompound comprising linear structures, cyclic, or cage structures, ormixtures of all three. Cyclic aluminoxane compounds having the formula:

wherein R is a linear or branched alkyl having from 1 to 10 carbonatoms, and n is an integer from 3 to about 10, are encompassed by thisinvention. The (AlRO)_(n) moiety shown here also constitutes therepeating unit in a linear aluminoxane. Thus, linear aluminoxanes havingthe formula:

wherein R is a linear or branched alkyl having from 1 to 10 carbonatoms, and n is an integer from 1 to about 50, are also encompassed bythis invention.

Further, aluminoxanes may also have cage structures of the formula R^(t)_(5m+α)R^(b) _(m−α)Al_(4m)O_(3m), wherein m is 3 or 4 and αis=n_(Al(3))−n_(O(2))+n_(O(4)), wherein n_(Al(3)) is the number of threecoordinate aluminum atoms, n_(O(2)) is the number of two coordinateoxygen atoms, n_(O(4)) is the number of 4 coordinate oxygen atoms, R^(t)is a terminal alkyl group, and R^(b) is a bridging alkyl group, and R isa linear or branched alkyl having from 1 to 10 carbon atoms.

Thus, aluminoxanes that may serve as optional cocatalysts in thisinvention are represented generally by formulas such as (R—Al—O)_(n),R(R—Al—O)_(n)AlR₂, and the like, wherein the R group is typically alinear or branched C₁–C₆ alkyl such as methyl, ethyl, propyl, butyl,pentyl, or hexyl, and n typically represents an integer from 1 to about50. Examples of aluminoxane compounds that may be used in accordancewith the present invention include, but are not limited to,methylaluminoxane, ethylaluminoxane, n-propylaluminoxane,iso-propylaluminoxane, n-butylaluminoxane, t-butyl-aluminoxane,sec-butylaluminoxane, iso-butylaluminoxane, 1-pentyl-aluminoxane,2-pentylaluminoxane, 3-pentylaluminoxane, iso-pentyl-aluminoxane,neopentylaluminoxane, or any combination thereof. Methyl aluminoxane,ethyl aluminoxane, and isobutyl aluminoxane are prepared fromtrimethylaluminum, triethylaluminum, or triisobutylaluminum,respectively, and sometimes are referred to as poly(methyl aluminumoxide), poly(ethyl aluminum oxide), and poly(isobutyl aluminum oxide),respectively. It is also within the scope of the invention to use analuminoxane in combination with a trialkylaluminum, such as thatdisclosed in U.S. Pat. No. 4,794,096, incorporated herein by referencein its entirety.

The present invention contemplates many values of n in the aluminoxaneformulas (R—Al—O)_(n) and R(R—Al—O)_(n)AlR₂, and n typically may be atleast about 3. However, depending upon how the organoaluminoxane isprepared, stored, and used, the value of n may vary within a singlesample of aluminoxane, and such combinations of organoaluminoxanes arecontemplated hereby.

In preparing the catalyst composition of this invention comprising anoptional aluminoxane, the molar ratio of the aluminum in the aluminoxaneto the metallocene in the composition may be from about 1:10 to about100,000:1, for example, from about 5:1 to about 15,000:1. The amount ofoptional aluminoxane added to a polymerization zone may be from about0.01 mg/L to about 1000 mg/L, from about 0.1 mg/L to about 100 mg/L, orfrom about 1 mg/L to about 50 mg/L.

Organoaluminoxanes may be prepared by various procedures that are wellknown in the art. Examples of organoaluminoxane preparations aredisclosed in U.S. Pat. Nos. 3,242,099 and 4,808,561, each of which isincorporated by reference herein in its entirety. For example, water inan inert organic solvent may be reacted with an aluminum alkyl compoundsuch as AlR₃ to form the desired organoaluminoxane compound. While notintending to be bound by this statement, it is believed that thissynthetic method can afford a mixture of both linear and cyclic(R—Al—O)_(n) aluminoxane species, both of which are encompassed by thisinvention. Alternatively, organoaluminoxanes may be prepared by reactingan aluminum alkyl compound, such as AlR₃ with a hydrated salt, such ashydrated copper sulfate, in an inert organic solvent.

5. The Optional Organoboron Cocatalyst

The present invention further provides a catalyst composition comprisingan optional organoboron cocatalyst. The organoboron compound maycomprise neutral boron compounds, borate salts, or any combinationthereof. For example, the organoboron compounds of this invention maycomprise a fluoroorgano boron compound, a fluoroorgano borate compound,or a combination thereof.

Any fluoroorgano boron or fluoroorgano borate compound known in the artcan be utilized with the present invention. Examples of fluoroorganoborate compounds that may be used as cocatalysts in the presentinvention include, but are not limited to, fluorinated aryl borates suchas N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate,triphenylcarbenium tetrakis(pentafluorophenyl)borate, lithiumtetrakis(pentafluorophenyl)borate, N,N-dimethylaniliniumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate, triphenylcarbeniumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate, and the like, includingmixtures thereof. Examples of fluoroorgano boron compounds that can beused as cocatalysts in the present invention include, but are notlimited to, tris(pentafluorophenyl)boron,tris[3,5-bis(trifluoromethyl)-phenyl]boron, and the like, includingmixtures thereof. Although not intending to be bound by the followingtheory, these examples of fluoroorgano borate and fluoroorgano boroncompounds, and related compounds, are thought to form“weakly-coordinating” anions when combined with organometal compounds,as disclosed in U.S. Pat. No. 5,919,983, incorporated herein byreference in its entirety.

Generally, any amount of organoboron compound may be used. According toone aspect of this invention, the molar ratio of the organoboroncompound to the metallocene compound in the composition may be fromabout 0.1:1 to about 10:1. Typically, the amount of the fluoroorganoboron or fluoroorgano borate compound used as a cocatalyst for themetallocenes may be from about 0.5 mole to about 10 moles of boroncompound per total moles of the metallocene compounds. According toanother aspect of this invention, the amount of fluoroorgano boron orfluoroorgano borate compound may be from about 0.8 mole to about 5 molesof boron compound per total moles of the metallocene compound.

6. The Optional Ionizing Ionic Compound Cocatalyst

The present invention further provides a catalyst composition comprisingan optional ionizing ionic compound cocatalyst. An ionizing ioniccompound is an ionic compound that can function to enhance the activityof the catalyst composition. While not intending to be bound by theory,it is believed that the ionizing ionic compound may be capable ofreacting with a metallocene compound and converting the metallocene intoone or more cationic metallocene compounds, or incipient cationicmetallocene compounds. Again, while not intending to be bound by theory,it is believed that the ionizing ionic compound may function as anionizing compound by completely or partially extracting an anionicligand, possibly a non-η⁵-alkadienyl ligand such as (X³) or (X⁴), fromthe metallocene. However, the ionizing ionic compound is an activatorregardless of whether it ionizes the metallocene, abstracts an (X³) or(X⁴) ligand in a fashion as to form an ion pair, weakens the metal-(X³)or metal-(X⁴) bond in the metallocene, simply coordinates to an (X³) or(X⁴) ligand, or activates the metallocene by some other mechanism.

Further, it is not necessary that the ionizing ionic compound activatethe metallocenes only. The activation function of the ionizing ioniccompound is evident in the enhanced activity of catalyst composition asa whole, as compared to a catalyst composition that does not compriseany ionizing ionic compound. It is also not necessary that the ionizingionic compound activate each of the metallocene compounds present, noris it necessary that it activate any of the metallocene compounds to thesame extent.

Examples of ionizing ionic compounds include, but are not limited to,the following compounds: tri(n-butyl)ammonium tetrakis(p-tolyl)borate,tri(n-butyl)ammonium tetrakis(m-tolyl)borate, tri(n-butyl)ammoniumtetrakis(2,4-dimethylphenyl)borate, tri(n-butyl)ammoniumtetrakis(3,5-dimethylphenyl)borate, tri(n-butyl)ammoniumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate, tri(n-butyl)ammoniumtetrakis(pentafluorophenyl)borate, N,N-dimethylaniliniumtetrakis(p-tolyl)borate, N,N-dimethylanilinium tetrakis(m-tolyl)borate,N,N-dimethylanilinium tetrakis(2,4-dimethylphenyl)borate,N,N-dimethylanilinium tetrakis(3,5-dimethylphenyl)borate,N,N-dimethylanilinium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate,N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate,triphenylcarbenium tetrakis(p-tolyl)borate, triphenylcarbeniumtetrakis(m-tolyl)borate, triphenylcarbeniumtetrakis(2,4-dimethylphenyl)borate, triphenylcarbeniumtetrakis(3,5-dimethylphenyl)borate, triphenylcarbeniumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate, triphenylcarbeniumtetrakis(pentafluorophenyl)borate, tropylium tetrakis(p-tolyl)borate,tropylium tetrakis(m-tolyl)borate, tropyliumtetrakis(2,4-dimethylphenyl)borate, tropyliumtetrakis(3,5-dimethylphenyl)borate, tropyliumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate, tropyliumtetrakis(pentafluorophenyl)borate, lithiumtetrakis(pentafluorophenyl)borate, lithium tetraphenylborate, lithiumtetrakis(p-tolyl)borate, lithium tetrakis(m-tolyl)borate, lithiumtetrakis(2,4-dimethylphenyl)borate, lithiumtetrakis(3,5-dimethylphenyl)borate, lithium tetrafluoroborate, sodiumtetrakis(pentafluorophenyl)borate, sodium tetraphenylborate, sodiumtetrakis(p-tolyl)borate, sodium tetrakis(m-tolyl)borate, sodiumtetrakis(2,4-dimethylphenyl)borate, sodiumtetrakis(3,5-dimethylphenyl)borate, sodium tetrafluoroborate, potassiumtetrakis-(pentafluorophenyl)borate, potassium tetraphenylborate,potassium tetrakis(p-tolyl)borate, potassium tetrakis(m-tolyl)borate,potassium tetrakis(2,4-dimethylphenyl)borate, potassiumtetrakis(3,5-dimethylphenyl)borate, potassium tetrafluoroborate,tri(n-butyl)ammonium tetrakis(p-tolyl)aluminate, tri(n-butyl)ammoniumtetrakis(m-tolyl)aluminate, tri(n-butyl)ammoniumtetrakis(2,4-dimethylphenyl)aluminate, tri(n-butyl)ammoniumtetrakis(3,5-dimethylphenyl)aluminate, tri(n-butyl)ammoniumtetrakis(pentafluorophenyl)aluminate, N,N-dimethylaniliniumtetrakis(p-tolyl)aluminate, N,N-dimethylaniliniumtetrakis(m-tolyl)aluminate, N,N-dimethylaniliniumtetrakis(2,4-dimethylphenyl)aluminate, N,N-dimethylaniliniumtetrakis(3,5-dimethylphenyl)aluminate, N,N-dimethylaniliniumtetrakis(pentafluorophenyl)aluminate, triphenylcarbeniumtetrakis(p-tolyl)aluminate, triphenylcarbeniumtetrakis(m-tolyl)aluminate, triphenylcarbeniumtetrakis(2,4-dimethylphenyl)aluminate, triphenyl-carbeniumtetrakis(3,5-dimethylphenyl)aluminate, triphenylcarbeniumtetrakis-(pentafluorophenyl)aluminate, tropyliumtetrakis(p-tolyl)aluminate, tropylium tetrakis(m-tolyl)aluminate,tropylium tetrakis(2,4-dimethylphenyl)aluminate, tropyliumtetrakis(3,5-dimethylphenyl)aluminate, tropyliumtetrakis(pentafluorophenyl)aluminate, lithiumtetrakis-(pentafluorophenyl)aluminate, lithium tetraphenylaluminate,lithium tetrakis(p-tolyl)aluminate, lithium tetrakis(m-tolyl)aluminate,lithium tetrakis(2,4-dimethylphenyl)aluminate, lithiumtetrakis(3,5-dimethylphenyl)aluminate, lithium tetrafluoroaluminate,sodium tetrakis(pentafluorophenyl)aluminate, sodiumtetraphenylaluminate, sodium tetrakis(p-tolyl)aluminate, sodiumtetrakis(m-tolyl)aluminate, sodiumtetrakis(2,4-dimethylphenyl)aluminate, sodiumtetrakis(3,5-dimethylphenyl)aluminate, sodium tetrafluoroaluminate,potassium tetrakis(pentafluorophenyl)aluminate, potassiumtetraphenylaluminate, potassium tetrakis(p-tolyl)aluminate, potassiumtetrakis(m-tolyl)aluminate, potassiumtetrakis(2,4-dimethylphenyl)aluminate, potassiumtetrakis(3,5-dimethylphenyl)aluminate, potassium tetrafluoroaluminate,and the like, or any combination thereof. However, the optional ionizingionic compounds that are useful in this invention are not limited tothese. Other examples of ionizing ionic compounds are disclosed in U.S.Pat. Nos. 5,576,259 and 5,807,938, each of which is incorporated hereinby reference in its entirety.

B. Olefin Monomer

Unsaturated reactants that may be useful with catalyst compositions andpolymerization processes of this invention include olefin compoundshaving from about 2 to about 30 carbon atoms per molecule and at leastone olefinic double bond. This invention encompasses homopolymerizationprocesses using a single olefin such as ethylene or propylene, as wellas copolymerization reactions with at least one different olefiniccompound. The resulting copolymer may comprise a major amount ofethylene (>50 mole percent) and a minor amount of comonomer <50 molepercent), though this is not a requirement. The comonomers that may becopolymerized with ethylene typically may have from three to about 20carbon atoms in their molecular chain.

Acyclic, cyclic, polycyclic, terminal (α), internal, linear, branched,substituted, unsubstituted, functionalized, and non-functionalizedolefins may be employed in this invention. For example, typicalunsaturated compounds that may be polymerized with the catalysts of thisinvention include, but are not limited to, propylene, 1-butene,2-butene, 3-methyl-1-butene, isobutylene, 1-pentene, 2-pentene,3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene, 2-hexene, 3-hexene,3-ethyl-1-hexene, 1-heptene, 2-heptene, 3-heptene, the four normaloctenes, the four normal nonenes, the five normal decenes, and mixturesof any two or more thereof. Cyclic and bicyclic olefins, including butnot limited to, cyclopentene, cyclohexene, norbornylene, norbornadiene,and the like, may also be polymerized as described above.

When a copolymer is desired, the monomer ethylene may be copolymerizedwith a comonomer. Examples of the comonomer include, but are not limitedto, propylene, 1-butene, 2-butene, 3-methyl-1-butene, isobutylene,1-pentene, 2-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene,2-hexene, 3-hexene, 3-ethyl-1-hexene, 1-heptene, 2-heptene, 3-heptene,the four normal octenes, the four normal nonenes, or the five normaldecenes. According to one aspect of the present invention, the comonomermay be selected from 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene,or styrene.

The amount of comonomer introduced into a reactor zone to produce thecopolymer generally may be from about 0.01 to about 50 weight percentcomonomer based on the total weight of the monomer and comonomer.According to another aspect of the present invention, the amount ofcomonomer introduced into a reactor zone may be from about 0.01 to about40 weight percent comonomer. According to still another aspect of thepresent invention, the amount of comonomer introduced into a reactorzone may be from about 0.1 to about 35 weight percent comonomer based onthe total weight of the monomer and comonomer. Alternatively, the amountof comonomer introduced into a reactor zone may be any amount sufficientto provide the above concentrations by weight.

While not intending to be bound by this theory, where branched,substituted, or functionalized olefins are used as reactants, it isbelieved that steric hindrance may impede and/or slow the polymerizationprocess. Thus, branched and/or cyclic portion(s) of the olefin removedsomewhat from the carbon-carbon double bond would not be expected tohinder the reaction in the way that the same olefin substituentssituated more proximate to the carbon-carbon double bond might.According to one aspect of the present invention, at least one reactantfor the catalyst compositions of this invention may be ethylene, so thepolymerizations are either homopolymerizations or copolymerizations witha different acyclic, cyclic, terminal, internal, linear, branched,substituted, or unsubstituted olefin. In addition, the catalystcompositions of this invention may be used in the polymerization ofdiolefin compounds including, but not limited to, 1,3-butadiene,isoprene, 1,4-pentadiene, and 1,5-hexadiene.

C. Preparation of the Catalyst Composition

The present invention encompasses a catalyst composition comprising thecontact product of a first metallocene compound, a second metallocenecompound, a third metallocene compound, at least one chemically-treatedsolid oxide, and at least one organoaluminum compound. The presentinvention further encompasses methods of making the catalyst compositioncomprising contacting a first metallocene compound, a second metallocenecompound, a third metallocene compound, at least one chemically-treatedsolid oxide, and at least one organoaluminum compound in any order.According to such methods, an active catalyst composition is obtainedwhen the catalyst components are contacted in any sequence or order.

One or more of the metallocene compounds may be precontacted with anolefinic monomer if desired, not necessarily the olefin monomer to bepolymerized, and an organoaluminum cocatalyst for a first period of timeprior to contacting this precontacted mixture with theactivator-support. The first period of time for contact, the precontacttime, between the metallocene compound or compounds, the olefinicmonomer, and the organoaluminum compound may typically range from timeabout 0.1 hour to about 24 hours, for example, from about 0.1 to about 1hour. Precontact times from about 10 minutes to about 30 minutes arealso typical.

Once the precontacted mixture of the metallocene compound or compounds,olefin monomer, and organoaluminum cocatalyst is contacted with theactivator-support, this composition (further comprising theactivator-support) is termed the “postcontacted mixture”. Thepostcontacted mixture optionally may be allowed to remain in contact fora second period of time, the postcontact time, prior to initiating thepolymerization process. Postcontact times between the precontactedmixture and the activator-support may range in time from about 0.1 hourto about 24 hours, for example, from about 0.1 hour to about 1 hour. Theprecontacting, the postcontacting step, or both may increase theproductivity of the polymer as compared to the same catalyst compositionthat is prepared without precontacting or postcontacting. However,neither a precontacting step nor a postcontacting step is required.

The postcontacted mixture may be heated at a temperature and for aduration sufficient to allow adsorption, impregnation, or interaction ofprecontacted mixture and the activator-support, such that a portion ofthe components of the precontacted mixture is immobilized, adsorbed, ordeposited thereon. Where heating is used, the postcontacted mixture maybe heated from between about 0° F. to about 150° F., for example, fromabout 40° F. to about 95° F.

According to one aspect of this invention, the molar ratio of the totalmoles of the metallocene compounds to the organoaluminum compound may befrom about 1:1 to about 1:10,000. According to another aspect of thisinvention, the molar ratio of the total moles of the metallocenecompounds combined to the organoaluminum compound may be from about 1:1to about 1:1,000. According to yet another aspect of this invention, themolar ratio of the total moles of the metallocene compounds combined tothe organoaluminum compound may be from about 1:1 to about 1:100. Thesemolar ratios reflect the ratio of the metallocene compounds to the totalamount of organoaluminum compound in both the precontacted mixture andthe postcontacted mixture combined.

When a precontacting step is used, the molar ratio of olefin monomer tototal moles of metallocene compound combined in the precontacted mixturemay be from about 1:10 to about 100,000:1, for example, from about 10:1to about 1,000:1.

The weight ratio of the activator-support to the organoaluminum compoundmay be from about 1:5 to about 1,000:1. The weight ratio of theactivator-support to the organoaluminum compound may be from about 1:3to about 100:1, for example, from about 1:1 to about 50:1.

According to a further aspect of this invention, the weight ratio of thetotal moles of the metallocene compound combined to theactivator-support may be from about 1:1 to about 1:1,000,000. Accordingto yet another aspect of this invention, the weight ratio of the totalmoles of the metallocene compound combined to the activator-support maybe from about 1:10 to about 1:10,000. According to still another aspectof this invention, the weight ratio of the total moles of themetallocene compound combined to the activator-support may be from about1:20 to about 1:1000.

Aluminoxane compounds are not required to form the catalyst compositionof the present invention. Thus, the polymerization proceeds in theabsence of aluminoxanes. Accordingly, the present invention may useAlR₃-type organoaluminum compounds and an activator-support in theabsence of aluminoxanes. While not intending to be bound by theory, itis believed that the organoaluminum compound likely does not activatethe metallocene catalyst in the same manner as an organoaluminoxane. Asa result, the present invention results in lower polymer productioncosts.

Additionally, no expensive borate compounds or MgCl₂ are required toform the catalyst composition of this invention. Nonetheless,aluminoxanes, organoboron compounds, ionizing ionic compounds,organozinc compounds, MgCl₂, or any combination thereof may beoptionally used in the catalyst composition of this invention. Further,cocatalysts such as aluminoxanes, organoboron compounds, ionizing ioniccompounds, organozinc compounds, or any combination thereof may beoptionally used as cocatalysts with the metallocene compound, either inthe presence or in the absence of the activator-support, and either inthe presence or in the absence of the organoaluminum compound.

According to one aspect of this invention, the catalyst activity of thecatalyst of this invention may be greater than or equal to about 100grams polyethylene per gram of chemically-treated solid oxide per hour(abbreviated gP/(gCTSO·hr)). According to another aspect of thisinvention, the catalyst of this invention may be characterized by anactivity of greater than or equal to about 250 gP/(gCTSO·hr). Accordingto still another aspect of this invention, the catalyst of thisinvention may be characterized by an activity of greater than or equalto about 500 gP/(gCTSO·hr). According to yet another aspect of thisinvention, the catalyst of this invention may be characterized by anactivity of greater than or equal to about 1000 gP/(gCTSO·hr). Accordingto a further aspect of this invention, the catalyst of this inventionmay be characterized by an activity of greater than or equal to about2000 gP/(gCTSO·hr). This activity is measured under slurrypolymerization conditions using isobutane as the diluent, at apolymerization temperature of about 90° C. and an ethylene pressure ofabout 550 psig. The reactor should have substantially no indication ofany wall scale, coating or other forms of fouling upon making thesemeasurements.

Any combination of the metallocene compounds, the activator-support, theorganoaluminum compound, and the olefin monomer, may be precontacted.When any precontacting occurs with an olefinic monomer, it is notnecessary that the olefin monomer used in the precontacting step be thesame as the olefin to be polymerized. Further, when a precontacting stepamong any combination of the catalyst components is employed for a firstperiod of time, this precontacted mixture may be used in a subsequentpostcontacting step between any other combination of catalyst componentsfor a second period of time. For example, all the catalyst componentsand 1-hexene may be used in a precontacting step for a first period oftime, and this precontacted mixture may then be contacted with theactivator-support to form a postcontacted mixture that is contacted fora second period of time prior to initiating the polymerization reaction.For example, the first period of time for contact, the precontact time,between any combination of the metallocene compounds, the olefinicmonomer, the activator-support, and the organoaluminum compound may befrom about 0.1 hour to about 24 hours, for example, from about 0.1 toabout 1 hour. Precontact times from about 10 minutes to about 30 minutesare also typical. The postcontacted mixture optionally may be allowed toremain in contact for a second period of time, the postcontact time,prior to initiating the polymerization process. According to one aspectof this invention, postcontact times between the precontacted mixtureand any remaining catalyst components may be from about 0.1 hour toabout 24 hours, for example, from about 0.1 hour to about 1 hour.

D. Use of the Catalyst Composition in Polymerization Processes

After catalyst activation, the catalyst composition is used tohomopolymerize ethylene or copolymerize ethylene with a comonomer.

The polymerization temperature may be from about 60° C. to about 280°C., for example, from about 70° C. to about 110° C. The polymerizationreaction typically begins in an inert atmosphere substantially free ofoxygen and under substantially anhydrous conditions. For example, a dry,inert atmosphere such as dry nitrogen or dry argon may be used.

The polymerization reaction pressure may be any pressure that does notterminate the polymerization reaction, and is typically a pressurehigher than the pretreatment pressures. According to one aspect of thepresent invention, the polymerization pressure may be from aboutatmospheric pressure to about 1000 psig. According to another aspect ofthe present invention, the polymerization pressure may be from about 50psig to about 800 psig. Further, hydrogen can be used in thepolymerization process of this invention to control polymer molecularweight.

Polymerizations using the catalysts of this invention may be carried outin any manner known in the art. Such processes that may be suitable foruse with the present invention include, but are not limited to, slurrypolymerizations, gas phase polymerizations, solution polymerizations,and multi-reactor combinations thereof. Thus, any polymerization zoneknown in the art to produce olefin-containing polymers can be utilized.For example, a stirred reactor may be utilized for a batch process, or aloop reactor or a continuous stirred reactor may be used for acontinuous process.

A typical polymerization method is a slurry polymerization process (alsoknown as the particle form process), which is well known in the art andis disclosed, for example, in U.S. Pat. No. 3,248,179, incorporated byreference herein in its entirety. Other polymerization methods of thepresent invention for slurry processes are those employing a loopreactor of the type disclosed in U.S. Pat. No. 3,248,179, incorporatedby reference herein in its entirety, and those utilized in a pluralityof stirred reactors either in series, parallel, or combinations thereof,where the reaction conditions are different in the different reactors.Suitable diluents used in slurry polymerization are well known in theart and include hydrocarbons that are liquids under reaction conditions.The term “diluent” as used in this disclosure does not necessarily meanan inert material, as this term is meant to include compounds andcompositions that may contribute to polymerization process. Examples ofhydrocarbons that may be used as diluents include, but are not limitedto, cyclohexane, isobutane, n-butane, propane, n-pentane, isopentane,neopentane, and n-hexane. Typically, isobutane may be used as thediluent in a slurry polymerization, as provided by U.S. Pat. Nos.4,424,341, 4,501,885, 4,613,484, 4,737,280, and 5,597,892, each of whichis incorporated by reference herein in its entirety.

Various polymerization reactors are contemplated by the presentinvention. As used herein, “polymerization reactor” includes anypolymerization reactor or polymerization reactor system capable ofpolymerizing olefin monomers to produce homopolymers or copolymers ofthe present invention. Such reactors may be slurry reactors, gas-phasereactors, solution reactors, or any combination thereof. Gas phasereactors may comprise fluidized bed reactors or tubular reactors. Slurryreactors may comprise vertical loops or horizontal loops. Solutionreactors may comprise stirred tank or autoclave reactors.

Polymerization reactors suitable for the present invention may compriseat least one raw material feed system, at least one feed system forcatalyst or catalyst components, at least one reactor system, at leastone polymer recovery system or any suitable combination thereof.Suitable reactors for the present invention further may comprise anyone, or combination of, a catalyst storage system, an extrusion system,a cooling system, a diluent recycling system, or a control system. Suchreactors may comprise continuous take-off and direct recycling ofcatalyst, diluent, and polymer. Generally, continuous processes maycomprise the continuous introduction of a monomer, a catalyst, and adiluent into a polymerization reactor and the continuous removal fromthis reactor of a suspension comprising polymer particles and thediluent.

Polymerization reactor systems of the present invention may comprise onetype of reactor per system or multiple reactor systems comprising two ormore types of reactors operated in parallel or in series. Multiplereactor systems may comprise reactors connected together to performpolymerization or reactors that are not connected. The polymer may bepolymerized in one reactor under one set of conditions, and thentransferred to a second reactor for polymerization under a different setof conditions.

According to one aspect of the invention, the polymerization reactorsystem may comprise at least one loop slurry reactor. Such reactors areknown in the art and may comprise vertical or horizontal loops. Suchloops may comprise a single loop or a series of loops. Multiple loopreactors may comprise both vertical and horizontal loops. The slurrypolymerization is typically performed in an organic solvent that candisperse the catalyst and polymer. Examples of suitable solvents includebutane, hexane, cyclohexane, octane, and isobutane. Monomer, solvent,catalyst and any comonomer may be continuously fed to a loop reactorwhere polymerization occurs. Polymerization may occur at lowtemperatures and pressures. Reactor effluent may be flashed to removethe solid resin.

According to yet another aspect of this invention, the polymerizationreactor may comprise at least one gas phase reactor. Such systems mayemploy a continuous recycle stream containing one or more monomerscontinuously cycled through the fluidized bed in the presence of thecatalyst under polymerization conditions. The recycle stream may bewithdrawn from the fluidized bed and recycled back into the reactor.Simultaneously, polymer product may be withdrawn from the reactor andnew or fresh monomer may be added to replace the polymerized monomer.Such gas phase reactors may comprise a process for multi-step gas-phasepolymerization of olefins, in which olefins are polymerized in thegaseous phase in at least two independent gas-phase polymerization zoneswhile feeding a catalyst-containing polymer formed in a firstpolymerization zone to a second polymerization zone.

According to still another aspect of the invention, the polymerizationreactor may comprise a tubular reactor. Tubular reactors may makepolymers by free radical initiation, or by employing the catalyststypically used for coordination polymerization. Tubular reactors mayhave several zones where fresh monomer, initiators, or catalysts areadded. Monomer may be entrained in an inert gaseous stream andintroduced at one zone of the reactor. Initiators, catalysts, and/orcatalyst components may be entrained in a gaseous stream and introducedat another zone of the reactor. The gas streams may be intermixed forpolymerization. Heat and pressure may be employed appropriately toobtain optimal polymerization reaction conditions.

According to yet another aspect of the invention, the polymerizationreactor may comprise a solution polymerization reactor. During solutionpolymerization, the monomer is contacted with the catalyst compositionby suitable stirring or other means. A carrier comprising an inertorganic diluent or excess monomer may be employed. If desired, themonomer may be brought in the vapor phase into contact with thecatalytic reaction product, in the presence or absence of liquidmaterial. The polymerization zone is maintained at temperatures andpressures that will result in the formation of a solution of the polymerin a reaction medium. Agitation may be employed during polymerization toobtain better temperature control and to maintain uniform polymerizationmixtures throughout the polymerization zone. Adequate means are utilizedfor dissipating the exothermic heat of polymerization. Thepolymerization may be effected in a batch manner, or in a continuousmanner. The reactor may comprise a series of at least one separator thatemploys high pressure and low pressure to separate the desired polymer.

According to a further aspect of the invention, the polymerizationreactor system may comprise the combination of two or more reactors.Production of polymers in multiple reactors may include several stagesin at least two separate polymerization reactors interconnected by atransfer device making it possible to transfer the polymers resultingfrom the first polymerization reactor into the second reactor. Thedesired polymerization conditions in one of the reactors may bedifferent from the operating conditions of the other reactors.Alternatively, polymerization in multiple reactors may include themanual transfer of polymer from one reactor to subsequent reactors forcontinued polymerization. Such reactors may include any combinationincluding, but not limited to, multiple loop reactors, multiple gasreactors, a combination of loop and gas reactors, a combination ofautoclave reactors or solution reactors with gas or loop reactors,multiple solution reactors, or multiple autoclave reactors.

After the polymer is produced, it may be formed into various articles,including but not limited to, household containers, utensils, filmproducts, drums, fuel tanks, pipes, geomembranes, and liners. Variousprocesses may be used to form these articles. Usually, additives andmodifiers are added to the polymer in order to provide desired effects.By using the invention described herein, articles can likely be producedat a lower cost, while maintaining most or all of the unique propertiesof polymers produced with metallocene catalysts.

The present invention is further illustrated by the following examples,which are not to be construed in any way as imposing limitations uponthe scope thereof. On the contrary, it is to be clearly understood thatresort may be had to various other aspects, embodiments, modifications,and equivalents thereof which, after reading the description herein, maybe suggested to one of ordinary skill in the art without departing fromthe spirit of the present invention or the scope of the appended claims.

EXAMPLES

For each of the following examples, various combinations of thefollowing four metallocenes were evaluated to determine their effect onpolymer attributes, particularly dart impact and haze. For convenience,the various metallocenes are set forth below with letter abbreviation:

A. Testing Procedure

Melt index (MI, g/10 min) was determined in accordance with ASTM D1238condition F at 190° C. with a 2,160 gram weight.

High load melt index (HLMI, g/10 min) was determined in accordance withASTM D1238 condition E at 190° C. with a 21,600 gram weight.

Polymer density was determined in grams per cubic centimeter (g/cc) on acompression molded sample, cooled at about 15° C. per hour, andconditioned for about 40 hours at room temperature in accordance withASTM D1505 and ASTM D1928, procedure C.

Molecular weights and molecular weight distributions were obtained usinga Waters 150 CV gel permeation chromatograph with trichlorobenzene (TCB)as the solvent, with a flow rate of 1 milliliter/minute at a temperatureof 140° C. 2,6-Di-t-butyl-4-methylphenol (BHT) at a concentration of 1.0gram per liter was used as a stabilizer in the TCB. An injection volumeof 220 liters was used with a nominal polymer concentration of 0.3gram/liter at room temperature. Dissolution of the sample in stabilizedTCB was carried out by heating at about 160–170° C. for 20 hours withoccasional, gentle agitation. The column was two Waters HT-6E columns(7.8 mm×300 mm). The columns were calibrated with a broad linearpolyethylene standard (Marlex® BHB 5003 resin) for which the molecularweight had been determined.

All the blown film samples were made on a laboratory-scale blown filmline using typical linear low-density (LLDPE) conditions as follows: 100mm (4 inch) die diameter, 1.5 mm (0.060 inch) die gap, 37.5 mm (1.5inch) diameter single-screw extruder fitted with a barrier screw with aMaddock mixing section at the end (L/D=24, 2.2:1 compression ratio), 115RPM screw speed [about 27 kg/h (60 lb/h) output rate], 2.5:1 blow upratio (BUR), “in-pocket” bubble with a “freeze line height” (FLH)between 20–28 cm (8–11 inch), 190° C. (375° F.) barrel and die settemperatures and 1 mil (25 micron) thick film. Cooling was accomplishedwith a Dual Lip air ring using ambient (laboratory) air at about 25° C.(75–80° F.). These particular processing conditions were chosen becausethe film properties so obtained are typically representative of thoseobtained from larger, commercial scale film blowing conditions.

Haze (%) was measured in accordance with the procedures specified inASTM D 1003-97. Clarity (%), also referred to as transparency, wasmeasured in accordance with the procedures specified in ASTM D 1746-97.Both measurements were made on a Haze Gard Plus™ instrument (Model 4725)manufactured by the BYK-Gardner® Company.

Dart impact strength was measured in accordance with ASTM D-1709 (methodA).

Machine (MD) and transverse (TD) direction Elmendorf tear strengths weremeasured on a Testing Machines Inc. tear tester (Model 83-11-00) inaccordance with ASTM D-1922.

Melt rheological characterizations were performed as follows.Small-strain (10%) oscillatory shear measurements were performed on aRheometrics Scientific, Inc. ARES rheometer using parallel-plategeometry. All theological tests were performed at 190° C. The complexviscosity |η*| versus frequency (ω) data were then curve fitted usingthe modified three parameter Carreau-Yasuda (CY) empirical model toobtain the zero shear viscosity—η₀, characteristic viscous relaxationtime—τ_(η), and the breadth parameter—α. The simplified Carreau-Yasuda(CY) empirical model is as follows.

${{{\eta*(\omega)}} = \frac{\eta_{0}}{\lbrack {1 + ( {\tau_{\eta}\omega} )^{a}} \rbrack^{{({1 - n})}/a}}},$wherein: |η*(ω)|=magnitude of complex shear viscosity;

η₀=zero shear viscosity;

τ_(η)=viscous relaxation time;

a=“breadth” parameter;

n=fixes the final power law slope, fixed at 2/11; and

ω=angular frequency of oscillatory shearing deformation.

Details of the significance and interpretation of the CY model andderived parameters may be found in: C. A. Hieber and H. H. Chiang,Rheol. Acta, 28, 321 (1989); C. A. Hieber and H. H. Chiang, Polym. Eng.Sci., 32, 931 (1992); and R. B. Bird, R. C. Armstrong and O. Hasseger,Dynamics of Polymeric Liquids, Volume 1, Fluid Mechanics, 2nd Edition,John Wiley & Sons (1987); each of which is incorporated herein byreference in its entirety. The CY “a” parameter is reported in thetables for the resins disclosed herein.

A “Quantachrome Autosorb-6 Nitrogen Pore Size Distribution Instrument”was used to determine specific surface area (“surface area”) andspecific pore volume (“pore volume”). This instrument was acquired fromthe Quantachrome Corporation, Syosset, N.Y.

B. Preparation of Metallocene Solutions

A solution of metallocene A and metallocene B was prepared by dissolving1.5 grams of bis(1,3-butylmethylcyclopentadienyl)dichlorozirconium and0.5 grams of bis(n-butylcyclopentadienyl)dichlorozirconium in about 250grams of heptane. This solution was transferred to a steel vessel andcombined with isobutane to bring the total weight to 40 pounds.

A solution of metallocene C was prepared by combining 0.2 grams ofbis(cyclopentadienyl)dichlorozirconium with 30 mL hexene-1, followed byadding 30 mL of 93 wt. % (neat) triethylaluminum. Next, 200 mL ofhexene-1 was added. The solution was then transferred to a steel vesseland combined with isobutane to bring the total weight to 40 pounds.

A solution of metallocene D was prepared by combining 0.2 grams of1,2-ethylenebis(1-indenyl)dichlorozirconium with 20 mL of dry heptane,followed by adding 10 mL of 93 wt. % (neat) triethylaluminum. Next, 280mL of heptane was added. After several hours, the solution wastransferred to a steel vessel and combined with isobutane to bring thetotal weight to 40 pounds.

C. Polymerization Conditions

Pilot plant polymerizations were conducted in a 23 gallon slurry loopreactor at a production rate of about 25 pounds of polymer per hour.Polymerization runs were also carried out under continuous particle formprocess conditions in a loop reactor by contacting a metallocenesolution in isobutane, triethylaluminum, and the solid activator in a 2L stirred autoclave with continuous output to the loop reactor.

The ethylene used was polymerization grade ethylene obtained from UnionCarbide Corporation (Houston, Tex.). The ethylene was purified bypassing through a column of alumina and activated at 250° C. (482° F.)in nitrogen.

The 1-hexene used in selected runs was polymerization grade 1-hexeneobtained from Chevron Phillips Chemical Company LP (The Woodlands, Tex.)that was purified by nitrogen purging and storage over 13× molecularsieve activated at 250° C. (482° F.) in nitrogen.

The loop reactor used was a liquid full, 15.2 cm diameter loop reactorhaving a volume of 23 gallons (87 L). Polymerization grade liquidisobutane previously obtained from the former Phillips Petroleum Company(Borger, Tex.) was used as the diluent. The isobutane was purified bydistillation, passed through a column of alumina, and activated at 250°C. (482° F.) in nitrogen.

The reaction was carried out at a pressure of about 580 psi (4 MPa) anda temperature of from about 79° C. (175° F.) to about 82° C. (179° F.)as indicated in Table 1. The residence time within the reactor was about1.25 hours. The solid activator was added through a 0.35 cc circulatingball-check feeder to the 2 L autoclave. The concentration of themetallocene in the reactor was from about 0.3 to about 0.7 parts permillion (ppm) of the diluent. For Examples 1 and 2, some hydrogen wasadded during the reaction to regulate the molecular weight. Polymer wasremoved from the reactor at a rate of about 25 lbs per hour andrecovered in a flash chamber. A Vulcan dryer was used to dry the polymerunder nitrogen at about 60° C. to about 80° C. (about 140° F. to about176° F.).

A triethylaluminum (TEA) cocatalyst obtained from Akzo Nobel Chemicals(Amsterdam, the Netherlands) was also used. The cocatalyst was obtainedas a one molar solution in heptane, but was further diluter to 1 wt.percent. The cocatalyst was added in an amount of about 14 ppm to about20 ppm of the diluent. To prevent static buildup of the reactor, a smallamount (less than 5 ppm by weight of diluent) of a commercial antistaticagent sold under the trade name STADIS 450 was added.

TABLE 1 Process Conditions for Various Experimental Runs. Example No. 12 3 4 5 6 7 8 9 10 11 Chemically- F—Si/Al F—Si/AL F—Si/AL F—Si/ALF—Si/AL F—Si/AL F—Si/AL F—Si/AL F—Si/AL F—Si/AL F—Si/AL Treated SolidOxide Metallocene A, B, C A, B, C A, B A, B A, B A, B A, B, D A, B, D A,B, D A, B A, B Solution 1 A:B 3:1 3:1 3:1 3:1 3:1 3:1 1.9:1 1.9:1 1.9:11.9:1 1.9:1 Solution 1, Total 0.33 0.32 0.55 0.46 0.35 0.46 0.32 0.370.38 0.57 0.64 Metallocene to Reactor (ppm) Solution 1, TEA None NoneNone None None None None None None None None Pretreat (mL) Solution 1,297 297 367 367 367 None None None None None None Hexene-1 Pretreat(mLs) Solution 2, C C C None None None None D D D None None or DSolution 2, 0.02 0.07 None None None None 0.05 0.06 0.11 None NoneMetallocene to Reactor (ppm) Solution 2, TEA 30 30 None None None None10.2 10.2 10.2 None None Pretreat (mL) Solution 2, 230 230 None NoneNone None None None None None None Hexene-1 Pretreat (mL) Autoclave25.20 24.47 24.81 24.80 25.07 13.30 13.09 12.77 12.90 13.38 12.41Residence Time (Min) Cocatalyst Type TEA TEA TEA TEA TEA TEA TEA TEA TEATEA TEA Cocatalyst (ppm) 14.92 14.89 14.99 14.41 14.95 19.68 18.88 19.6019.49 19.53 19.61 Rx Temp (° F.) 175.0 175.0 174.8 175.0 175.1 179.2176.2 176.5 176.4 179.3 179.2 Ethylene (mol %) 13.97 13.86 13.65 13.9214.09 15.66 14.40 13.86 15.03 13.02 13.80 1-hexene (mol %) 6.64 6.612.68 3.08 2.86 15.52 11.91 12.57 10.93 11.03 10.99 C6═/C2═ (Mole 0.480.48 0.20 0.22 0.20 0.99 0.83 0.91 0.73 0.85 0.80 Ratio) H₂ (mole %)0.0011 0.0011 0 0 0 0.003 0 0 0 0 0 C2═ Feed 25.81 25.8 25.80 25.8025.81 29.80 29.57 29.59 29.61 29.61 29.59 Rate (lb/hr) 1-Hexene Feed9.73 9.91 11.17 11.40 11.21 11.84 10.53 11.04 11.14 11.01 11.13 Rate(lb/hr) Total iC4 Flow 48.26 48.24 48.21 48.14 48.27 54.00 53.55 53.6051.99 52.98 53.00 Rate (lb/hr) Solids Conc. 25.90 26.10 24.80 25.4024.70 29.50 28.70 28.90 28.80 29.00 28.00 wt. % Polymer 22.11 22.3321.50 22.00 21.44 27.67 26.22 26.33 26.11 26.56 25.75 Production (lb/hr)Density (pellets) 0.9171 0.9165 0.9177 0.9176 0.9163 0.9160 0.91830.9171 0.9174 0.9182 0.9194 (g/cc) CTSO (RPH) 53 51 35 34 39 22 28 26 2526 26 Mass Balance n/a n/a 1906 1906 1906 2854 2377 2377 2377 2825 2825Productivity (lb/lb) Ash Productivity 2222 2632 3571 2778 3226 3030 15312183 3448 3571 2326 (lb/lb) Ash (wt %) 0.0450 0.0380 0.0280 0.03600.0310 0.0330 0.0653 0.0458 0.0290 0.0280 0.0430 HLMI 19.35 17.45 16.2215.63 13.60 16.53 18.59 20.40 24.53 18.17 22.14 Melt Index (MI) 1.090.89 0.92 0.90 0.80 0.98 1.06 1.16 1.32 1.21 1.31 HLMI/MI 18 20 18 17 1717 18 18 19 15 17 Carreau-Yasuda 0.548 0.36 0.648 0.647 0.668 0.6550.517 0.544 0.484 0.633 0.624 a value Recoverable 16 58 9 9 9 8 21 17 249 9 Shear Parameter × 1000

D. Examples 1–6

Various amounts of metallocene C were combined with metallocene A andmetallocene B to determine the effect on the resulting polymer haze.Table 2 summarizes the results. As is readily apparent, the presence ofmetallocene C significantly reduced the haze of the resulting polymerfilm.

TABLE 2 Effect of Metallocene C on Polymer Properties. Dart MD TD WeightDensity MI Impact Tear Tear Haze Clarity Example Metallocene ratio(g/cc) (dg/min) (g) (g) (g) (%) (%) 1 A + B + C 3:1:0.24 0.9171.11 >1400 179 465 5.3 98.8 2 A + B + C 3:1:0.88 0.916 0.97 >1400 130382 8.2 96.4 3 A + B 3:1 0.917 0.98 921 246 354 10.0 98.7 4 A + B 3:10.917 0.96 973 225 367 10.1 98.2 5 A + B 3:1 0.916 0.82 >1400 176 33410.3 97.5 6 A + B 3:1 0.916 0.98 >1400 217 402 13.3 97.6

E. Examples 7–11

Various amounts of metallocene D were combined with metallocene A andmetallocene B to determine the effect on the resulting polymer haze.Table 3 summarizes the results. In Examples 7 and 8, the haze of thepolymer film was significantly reduced.

TABLE 3 Effect of Metallocene D on Polymer Properties. Dart MD TD WeightDensity MI Impact Tear Tear Haze Clarity Example Metallocene ratio(g/cc) (dg/min) (g) (g) (g) (%) (%) 7 A + B + D 1.9:1:0.45 0.918 1.06536 172 557 8.3 98.5 8 A + B + D 1.9:1:0.47 0.917 1.16 >1400 196 488 9.497.8 9 A + B + D 1.9:1:0.84 0.917 1.32 1323 142 526 11.9 98.7 10 A + B1.9:1 0.918 1.21 >1400 214 389 10.2 97.6 11 A + B 1.9:1 0.919 1.31 694275 469 17.0 94.4

In sum, the present invention provides a catalyst composition and amethod for producing a polymer that can be used to produce film havinglow haze. The catalyst composition includes a first metallocenecompound, a second metallocene compound, a third metallocene compound, achemically-treated solid oxide, and an organoaluminum compound. At leastone of the metallocene compounds produces some long chain branching. Thefirst metallocene compound and the second metallocene compound aredifferent from each other and have the formula:(RCpR′)₂(X¹)(X²)M¹;wherein each R is an aliphatic group having from about 3 to about 10carbon atoms, each R′ independently is H or an aliphatic group having upto 2 carbon atoms, (X¹) and (X²) independently are a halide, and M¹ isZr or Hf. The third metallocene compound has the formula:(Cp)₂(X³)(X⁴)M²;  1)wherein (X³) and (X⁴) independently are a halide, and M² is Zr or Hf; or(X⁵)(X⁶)(X⁷)(X⁸)M³;  2)wherein (X⁵) and (X⁶) independently are a cyclopentadienyl or an indenylgroup, (X⁵) and (X⁶) are connected by a methylene, an ethylene, or adimethyl silicon bridging group, (X⁷) and (X⁸) independently are ahalide, and M³ is Zr or Hf.

While costly aluminoxanes, organoborates, and ionizing ionic compoundsare not required by the present invention, they may be used as desired.Accordingly, catalyst compositions made in accordance with the presentinvention may be substantially free of aluminoxanes, organoborates, andionizing ionic compounds. As demonstrated by the above examples, the useof a tri-catalyst system, such as those described herein, producespolyolefin films having a desirably low haze while maintaining otherphysical attributes, such as dart impact.

The foregoing description has been presented for purposes ofillustration and description. It is not intended to be exhaustive or tolimit the invention to the precise examples or embodiments disclosed.Obvious modifications or variations are possible in light of the aboveteachings. The embodiment or embodiments discussed were chosen anddescribed to provide the best illustration of the principles of theinvention and its practical application to thereby enable one ofordinary skill in the art to utilize the invention in variousembodiments and with various modifications as are suited to theparticular use contemplated. All such modifications and variations arewithin the scope of the invention as determined by the appended claimswhen interpreted in accordance with the breadth to which they are fairlyand legally entitled.

1. A catalyst composition comprising a first metallocene compound, asecond metallocene compound, a third metallocene compound, achemically-treated solid oxide, and an organoaluminum compound, wherein:(a) the first metallocene compound and the second metallocene compoundare different from each other and have the formula:(RCpR′)₂(X¹)(X²)M¹;  wherein each R is an aliphatic group having fromabout 3 to about 10 carbon atoms;  wherein each R′ independently is H oran aliphatic group having up to 2 carbon atoms;  wherein (X¹) and (X²)independently are a halide;  wherein M¹ is Zr or Hf; and (b) the thirdmetallocene compound has the formula:(Cp)₂(X³)(X⁴)M²;  1)  wherein (X³) and (X⁴) independently are a halide; wherein M² is Zr or Hf; or(X⁵)(X⁶)(X⁷)(X⁸)M³;  2)  wherein (X⁵) and (X⁶) independently are acyclopentadienyl or an indenyl group;  wherein (X⁵) and (X⁶) areconnected by a methylene, an ethylene, or a dimethyl silicon bridginggroup;  wherein (X⁷) and (X⁸) independently are a halide;  wherein M³ isZr or Hf; and wherein Cp is a cyclopentadienyl group.
 2. The catalystcomposition of claim 1, wherein R is n-butyl.
 3. The catalystcomposition of claim 1, wherein R′ is ethyl.
 4. The catalyst compositionof claim 1, wherein the first metallocene compound isbis(n-butylcyclopentadienyl)dichlorozirconium.
 5. The catalystcomposition of claim 1, wherein the second metallocene compound isbis(1,3-butylmethylcyclopentadienyl)dichlorozirconium.
 6. The catalystcomposition of claim 1, wherein the third metallocene compound isbis(cyclopentadienyl)dichlorozirconium.
 7. The catalyst composition ofclaim 1, wherein the third metallocene compound is1,2-ethylenebis(1-indenyl)dichlorozirconium.
 8. The catalyst compositionof claim 1, wherein the chemically-treated solid oxide is fluoridedalumina, chlorided alumina, bromided alumina, sulfated alumina,fluorided silica-alumina, chlorided silica-alumina, bromidedsilica-alumina, sulfated silica-alumina, fluorided silica-zirconia,chlorided silica-zirconia, bromided silica-zirconia, sulfatedsilica-zirconia, triflated silica-alumina, silica treated with afluoroborate, or any combination thereof.
 9. The catalyst composition ofclaim 1, wherein the chemically-treated solid oxide comprises a solidoxide treated with an electron-withdrawing anion, wherein the solidoxide is silica, alumina, silica-alumina, aluminum phosphate,heteropolytungstates, titania, zirconia, magnesia, boria, zinc oxide,mixed oxides thereof or any combination thereof; and theelectron-withdrawing anion is fluoride, chloride, bromide, phosphate,triflate, bisulfate, sulfate, or any combination thereof.
 10. Thecatalyst composition of claim 9, wherein the chemically-treated solidoxide further comprises a metal or metal ion, wherein the metal or metalion is zinc, nickel, vanadium, silver, copper, gallium, tin, tungsten,molybdenum, or any combination thereof.
 11. The catalyst composition ofclaim 1, wherein the chemically-treated solid oxide is zinc-impregnatedchlorided alumina, zinc-impregnated fluorided alumina, zinc-impregnatedchlorided silica-alumina, zinc-impregnated fluorided silica-alumina,zinc-impregnated sulfated alumina, or any combination thereof.
 12. Thecatalyst composition of claim 1, wherein the organoaluminum compound hasthe formula:Al(X⁹)_(n)(X¹⁰)_(3−n); wherein (X⁹) is a hydrocarbyl having from 1 toabout 20 carbon atoms, (X¹⁰) is an alkoxide or an aryloxide having from1 to about 20 carbon atoms, a halide, or a hydride, and n is a numberfrom 1 to 3, inclusive.
 13. The catalyst composition of claim 1, whereinthe organoaluminum compound is trimethylaluminum, triethylaluminum,tri-n-propylaluminum, diethylaluminum ethoxide, tri-n-butylaluminum,diisobutylaluminum hydride, triisobutylaluminum, diethylaluminumchloride, or any combination thereof.
 14. The catalyst composition ofclaim 1, wherein the weight ratio of the organoaluminum compound to thechemically-treated solid oxide is from about 10:1 to about 1:1000. 15.The catalyst composition of claim 1, further comprising a cocatalystselected from at least one aluminoxane, at least one organozinccompound, at least one organoboron compound, at least one ionizing ioniccompound, or any combination thereof.
 16. The catalyst composition ofclaim 1, further comprising an at least one aluminoxane compound,wherein the aluminoxane is: a cyclic aluminoxane having the formula:

wherein R is a linear or branched alkyl having from 1 to 10 carbonatoms, and n is an integer from 3 to about 10; a linear aluminoxanehaving the formula:

wherein R is a linear or branched alkyl having from 1 to 10 carbonatoms, and n is an integer from 1 to about 50; a cage aluminoxane havingthe formula R^(t) _(5m+α)R^(b) _(m−α)Al_(4m)O_(3m), wherein m is 3 or 4and α is=n_(Al(3))−n_(O(2))+n_(O(4)); wherein n_(Al(3)) is the number ofthree coordinate aluminum atoms, n_(O(2)) is the number of twocoordinate oxygen atoms, n_(O(4)) is the number of 4 coordinate oxygenatoms, R^(t) represents a terminal alkyl group, and R^(b) represents abridging alkyl group; wherein R is a linear or branched alkyl havingfrom 1 to 10 carbon atoms; or any combination thereof.
 17. The catalystcomposition of claim 1, further comprising N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate, lithiumtetrakis(pentafluorophenyl)borate, triphenylcarbeniumtetrakis(pentafluorophenyl)borate, N,N-dimethylaniliniumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate, triphenylcarbeniumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate,tris(pentafluorophenyl)boron, tris[3,5-bis(trifluoromethyl)phenyl]boron,or any mixture thereof.
 18. The catalyst composition of claim 1, furthercomprising an ionizing ionic compound, wherein the ionizing ioniccompound is tri(n-butyl)ammonium tetrakis(p-tolyl)borate,tri(n-butyl)ammonium tetrakis(m-tolyl)borate, tri(n-butyl)ammoniumtetrakis(2,4-dimethylphenyl)borate, tri(n-butyl)ammoniumtetrakis(3,5-dimethylphenyl)borate, tri(n-butyl)ammoniumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate, tri(n-butyl)ammoniumtetrakis(pentafluorophenyl)borate, N,N-dimethylaniliniumtetrakis(p-tolyl)borate, N,N-dimethylanilinium tetrakis(m-tolyl)borate,N,N-dimethylanilinium tetrakis(2,4-dimethylphenyl)borate,N,N-dimethylanilinium tetrakis(3,5-dimethylphenyl)borate,N,N-dimethylanilinium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate,N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate,triphenylcarbenium tetrakis(p-tolyl)borate, triphenylcarbeniumtetrakis(m-tolyl)borate, triphenylcarbeniumtetrakis(2,4-dimethylphenyl)borate, triphenylcarbeniumtetrakis(3,5-dimethylphenyl)borate, triphenylcarbeniumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate, triphenylcarbeniumtetrakis(pentafluorophenyl)borate, tropylium tetrakis(p-tolyl)borate,tropylium tetrakis(m-tolyl)borate, tropyliumtetrakis(2,4-dimethylphenyl)borate, tropyliumtetrakis(3,5-dimethylphenyl)borate, tropyliumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate, tropyliumtetrakis(pentafluorophenyl)borate, lithiumtetrakis(pentafluorophenyl)borate, lithium tetraphenylborate, lithiumtetrakis(p-tolyl)borate, lithium tetrakis(m-tolyl)borate, lithiumtetrakis(2,4-dimethylphenyl)borate, lithiumtetrakis(3,5-dimethylphenyl)borate, lithium tetrafluoroborate, sodiumtetrakis(pentafluorophenyl)borate, sodium tetraphenylborate, sodiumtetrakis(p-tolyl)borate, sodium tetrakis(m-tolyl)borate, sodiumtetrakis(2,4-dimethylphenyl)borate, sodiumtetrakis(3,5-dimethylphenyl)borate, sodium tetrafluoroborate, potassiumtetrakis(pentafluorophenyl)borate, potassium tetraphenylborate,potassium tetrakis(p-tolyl)borate, potassium tetrakis(m-tolyl)borate,potassium tetrakis(2,4-dimethylphenyl)borate, potassiumtetrakis(3,5-dimethylphenyl)borate, potassium tetrafluoroborate,tri(n-butyl)ammonium tetrakis(p-tolyl)aluminate, tri(n-butyl)ammoniumtetrakis(m-tolyl)aluminate, tri(n-butyl)ammoniumtetrakis(2,4-dimethylphenyl)aluminate, tri(n-butyl)ammoniumtetrakis(3,5-dimethylphenyl)aluminate, tri(n-butyl)ammoniumtetrakis(pentafluorophenyl)aluminate, N,N-dimethylaniliniumtetrakis(p-tolyl)aluminate, N,N-dimethylaniliniumtetrakis(m-tolyl)aluminate, N,N-dimethylaniliniumtetrakis(2,4-dimethylphenyl)aluminate, N,N-dimethylaniliniumtetrakis(3,5-dimethylphenyl)aluminate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)aluminate, triphenylcarbeniumtetrakis(p-tolyl)aluminate, triphenylcarbeniumtetrakis(m-tolyl)aluminate, triphenylcarbeniumtetrakis(2,4-dimethylphenyl)aluminate, triphenylcarbeniumtetrakis(3,5-dimethylphenyl)aluminate, triphenylcarbeniumtetrakis(pentafluorophenyl)aluminate, tropyliumtetrakis(p-tolyl)aluminate, tropylium tetrakis(m-tolyl)aluminate,tropylium tetrakis(2,4-dimethylphenyl)aluminate, tropyliumtetrakis(3,5-dimethylphenyl)aluminate, tropyliumtetrakis(pentafluorophenyl)aluminate, lithiumtetrakis(pentafluorophenyl)aluminate, lithium tetraphenylaluminate,lithium tetrakis(p-tolyl)aluminate, lithium tetrakis(m-tolyl)aluminate,lithium tetrakis(2,4-dimethylphenyl)aluminate, lithiumtetrakis(3,5-dimethylphenyl)aluminate, lithium tetrafluoroaluminate,sodium tetrakis(pentafluorophenyl)aluminate, sodiumtetraphenylaluminate, sodium tetrakis(p-tolyl)aluminate, sodiumtetrakis(m-tolyl)aluminate, sodiumtetrakis(2,4-dimethylphenyl)aluminate, sodiumtetrakis(3,5-dimethylphenyl)aluminate, sodium tetrafluoroaluminate,potassium tetrakis(pentafluorophenyl)aluminate, potassiumtetraphenylaluminate, potassium tetrakis(p-tolyl)aluminate, potassiumtetrakis(m-tolyl)aluminate, potassiumtetrakis(2,4-dimethylphenyl)aluminate, potassiumtetrakis(3,5-dimethylphenyl)aluminate, potassium tetrafluoroaluminate,or any combination thereof.
 19. A catalyst composition comprising afirst metallocene compound, a second metallocene compound, a thirdmetallocene compound, a chemically-treated solid oxide, and anorganoaluminum compound, wherein: (a) the first metallocene compound andthe second metallocene compound are different from each other and havethe formula:(RCpR′)₂(X¹)(X²)M¹; wherein each R is a linear aliphatic group havingfrom about 3 to about 10 carbon atoms; wherein each R¹ independently isH or a linear aliphatic group having up to 2 carbon atoms; wherein (X¹)and (X²) independently are a halide; wherein M¹ is Zr or Hf; (b) thethird metallocene compound has the formula:(Cp)₂(X³)(X⁴)M²;  1) wherein (X³) and (X⁴) independently are a halide;wherein M² is Zr or Hf; or(X⁵)(X⁶)(X⁷)(X⁸)M³;  2) wherein (X⁵) and (X⁶) independently are acyclopentadienyl or an indenyl group; wherein (X⁵) and (X⁶) areconnected by an ethylene bridging group; wherein (X⁷) and (X⁸)independently are a halide; wherein M³ is Zr or Hf; and wherein Cp is acyclopentadienyl group; (c) the chemically-treated solid oxide comprisesa fluorided solid oxide; and (d) the organoaluminum compound has theformula:Al(X⁹)_(n)(X¹⁰)_(3−n); wherein (X⁹) is a hydrocarbyl having from 1 toabout 20 carbon atoms, (X¹⁰) is an alkoxide or an aryloxide having from1 to about 20 carbon atoms, a halide, or a hydride, and n is a numberfrom 1 to 3, inclusive.
 20. The catalyst composition of claim 19,wherein the first metallocene compound isbis(n-butylcyclopentadienyl)dichlorozirconium, and the third metallocenecompound is bis(cyclopentadienyl)dichlorozirconium.
 21. The catalystcomposition of claim 19, wherein the first metallocene compound isbis(n-butylcyclopentadienyl)dichlorozirconium, and the third metallocenecompound is 1,2-ethylenebis(1-indenyl)dichlorozirconium.
 22. Thecatalyst composition of claim 19, wherein the second metallocenecompound is bis(1,3-butylmethylcyclopentadienyl)dichlorozirconium, andthe third metallocene compound isbis(cyclopentadienyl)dichlorozirconium.
 23. The catalyst composition ofclaim 19, wherein the second metallocene compound isbis(1,3-butylmethylcyclopentadienyl)dichlorozirconium, and the thirdmetallocene compound is 1,2-ethylenebis(1-indenyl)dichlorozirconium. 24.The catalyst composition of claim 19, wherein the organoaluminumcompound is trimethylaluminum, triethylaluminum, tri-n-propylaluminum,diethylaluminum ethoxide, tri-n-butylaluminum, diisobutylaluminumhydride, triisobutylaluminum, diethylaluminum chloride, or anycombination thereof.
 25. A catalyst composition comprising the contactproduct of a first metallocene compound, a second metallocene compound,a third metallocene compound, a chemically-treated solid oxide, and anorganoaluminum compound, wherein: (a) the first metallocene compound andthe second metallocene compound are different from each other and havethe formula:(RCpR′)₂(X¹)(X²)M¹; wherein each R is an aliphatic group having fromabout 3 to about 10 carbon atoms; wherein each R′ independently is H oran aliphatic group having up to 2 carbon atoms; wherein (X¹) and (X²)independently are a halide; wherein M¹ is Zr or Hf; (b) the thirdmetallocene compound has the formula:(Cp)₂(X³)(X⁴)M²;  1)  wherein (X³) and (X⁴) independently are a halide; wherein M² is Zr or Hf; or(X⁵)(X⁶)(X⁷)(X⁸)M³;  2)  wherein (X⁵) and (X⁶) independently are acyclopentadienyl or an indenyl group;  wherein (X⁵) and (X⁶) areconnected by a methylene, an ethylene, or a dimethyl silicon bridginggroup;  wherein (X⁷) and (X⁸) independently are a halide;  wherein M³ isZr or Hf; and wherein Cp is a cyclopentadienyl group; (c) thechemically-treated solid oxide comprises a solid oxide treated with anelectron-withdrawing anion; and (d) the organoaluminum compound has theformula:Al(X⁹)_(n)(X¹⁰)_(3−n); wherein (X⁹) is a hydrocarbyl having from 1 toabout 20 carbon atoms, (X¹⁰) is an alkoxide or an aryloxide having from1 to about 20 carbon atoms, a halide, or a hydride, and n is a numberfrom 1 to 3, inclusive.
 26. The catalyst composition of claim 25,wherein R is n-butyl.
 27. The catalyst composition of claim 25, whereinR′ is ethyl.
 28. The catalyst composition of claim 25, wherein the firstmetallocene compound is bis(n-butylcyclopentadienyl)dichlorozirconiumand the second metallocene compound isbis(1,3-butylmethylcyclopentadienyl)dichlorozirconium.
 29. The catalystcomposition of claim 25, wherein the third metallocene compound isbis(cyclopentadienyl)dichlorozirconium.
 30. The catalyst composition ofclaim 25, wherein the third metallocene compound is1,2-ethylenebis(1-indenyl)dichlorozirconium.
 31. The catalystcomposition of claim 25, wherein the chemically-treated solid oxide isfluorided alumina, chlorided alumina, bromided alumina, sulfatedalumina, fluorided silica-alumina, chlorided silica-alumina, bromidedsilica-alumina, sulfated silica-alumina, fluorided silica-zirconia,chlorided silica-zirconia, bromided silica-zirconia, sulfatedsilica-zirconia, triflated silica-alumina, silica treated with afluoroborate, or any combination thereof.
 32. The catalyst compositionof claim 25, wherein the chemically-treated solid oxide comprises asolid oxide treated with an electron-withdrawing anion, wherein thesolid oxide is silica, alumina, silica-alumina, aluminum phosphate,heteropolytungstates, titania, zirconia, magnesia, boria, zinc oxide,mixed oxides thereof, or any combination thereof; and theelectron-withdrawing anion is fluoride, chloride, bromide, phosphate,triflate, bisulfate, sulfate, or any combination thereof.
 33. Thecatalyst composition of claim 32, wherein the chemically-treated solidoxide further comprises a metal or metal ion, wherein the metal or metalion is zinc, nickel, vanadium, silver, copper, gallium, tin, tungsten,molybdenum, or any combination thereof.
 34. The catalyst composition ofclaim 25, wherein the chemically-treated solid oxide is zinc-impregnatedchlorided alumina, zinc-impregnated fluorided alumina, zinc-impregnatedchlorided silica-alumina, zinc-impregnated fluorided silica-alumina,zinc-impregnated sulfated alumina, or any combination thereof.
 35. Thecatalyst composition of claim 25, wherein the organoaluminum compound istrimethylaluminum, triethylaluminum, tri-n-propylaluminum,diethylaluminum ethoxide, tri-n-butylaluminum, diisobutylaluminumhydride, triisobutylaluminum, diethylaluminum chloride, or anycombination thereof.
 36. The catalyst composition of claim 25, whereinthe weight ratio of the organoaluminum compound to thechemically-treated solid oxide is from about 10:1 to about 1:1000. 37.The catalyst composition of claim 25, further comprising at least onealuminoxane, at least one organozinc compound, at least one organoboroncompound, at least one ionizing ionic compound, or any combinationthereof.
 38. A catalyst composition comprising:bis(1,3-butylmethylcyclopentadienyl)dichlorozirconium;bis(n-butylcyclopentadienyl)dichlorozirconium; a third metallocenecompound having the formula:(Cp)₂(X³)(X⁴)M²;  1)  wherein (X³) and (X⁴) independently are a halide; wherein M² is Zr or Hf; and  wherein Cp is a cyclopentadienyl group; or(X⁵)(X⁶)(X⁷)(X⁸)M³;  2)  wherein (X⁵) and (X⁶) independently are acyclopentadienyl or an indenyl group;  wherein (X⁵) and (X⁶) areconnected by an ethylene bridging group;  wherein (X⁷) and (X⁸)independently are a halide;  wherein M³ is Zr or Hf; at least onechemically-treated solid oxide; and at least one organoaluminumcompound.
 39. The catalyst composition of claim 38, wherein the thirdmetallocene compound is bis(cyclopentadienyl)dichlorozirconium.
 40. Thecatalyst composition of claim 38, wherein the third metallocene compoundis 1,2-ethylenebis(1-indenyl)dichlorozirconium.
 41. The catalystcomposition of claim 38, wherein the chemically-treated solid oxide isfluorided alumina, chlorided alumina, bromided alumina, sulfatedalumina, fluorided silica-alumina, chlorided silica-alumina, bromidedsilica-alumina, sulfated silica-alumina, fluorided silica-zirconia,chlorided silica-zirconia, bromided silica-zirconia, sulfatedsilica-zirconia, triflated silica-alumina, silica treated with afluoroborate, or any combination thereof.
 42. The catalyst compositionof claim 38, wherein the chemically-treated solid oxide comprises asolid oxide treated with an electron-withdrawing anion, wherein thesolid oxide is silica, alumina, silica-alumina, aluminum phosphate,heteropolytungstates, titania, zirconia, magnesia, boria, zinc oxide,mixed oxides thereof, or any combination thereof; and theelectron-withdrawing anion is fluoride, chloride, bromide, phosphate,triflate, bisulfate, sulfate, or any combination thereof.
 43. Thecatalyst composition of claim 38, wherein the organoaluminum compoundhas the formula:Al(X⁹)_(n)(X¹⁰)_(3−n); wherein (X⁹) is a hydrocarbyl having from 1 toabout 20 carbon atoms, (X¹⁰) is an alkoxide or an aryloxide having from1 to about 20 carbon atoms, a halide, or a hydride, and n is a numberfrom 1 to 3, inclusive.
 44. A catalyst composition comprising thecontact product of bis(n-butylcyclopentadienyl)dichlorozirconium,bis(1,3-butylmethylcyclopentadienyl)dichlorozirconium,bis(cyclopentadienyl)dichlorozirconium, a chemically-treated solidoxide, and an organoaluminum compound.
 45. The catalyst composition ofclaim 44, wherein the chemically-treated solid oxide is fluoridedalumina.
 46. The catalyst composition of claim 44, wherein theorganoaluminum compound is triethylaluminum.
 47. A catalyst compositioncomprising the contact product ofbis(n-butylcyclopentadienyl)dichlorozirconium,bis(1,3-butylmethylcyclopentadienyl)dichlorozirconium,1,2-ethylenebis(1-indenyl)dichlorozirconium, a chemically-treated solidoxide, and an organoaluminum compound.
 48. The catalyst composition ofclaim 47, wherein the chemically-treated solid oxide is fluoridedalumina.
 49. The catalyst composition of claim 47, wherein theorganoaluminum compound is triethylaluminum.
 50. A process for producinga catalyst composition comprising contacting a first metallocenecompound, a second metallocene compound, a third metallocene compound, achemically-treated solid oxide, and an organoaluminum compound, wherein:(a) the first metallocene compound and the second metallocene compoundare different from each other and have the formula:(RCpR′)₂(X¹)(X²)M¹; wherein each R is an aliphatic group having fromabout 3 to about 10 carbon atoms; wherein each R′ independently is H oran aliphatic group having up to 2 carbon atoms; wherein (X¹) and (X²)independently are a halide; wherein M¹ is Zr or Hf; (b) the thirdmetallocene compound has the formula:(Cp)₂(X³)(X⁴)M²;  1)  wherein (X³) and (X⁴) independently are a halide; wherein M² is Zr or Hf; or(X⁵)(X⁶)(X⁷)(X⁸)M³;  2)  wherein (X⁵) and (X⁶) independently are acyclopentadienyl or an indenyl group;  wherein (X⁵) and (X⁶) areconnected by a methylene, an ethylene, or a dimethyl silicon bridginggroup;  wherein (X⁷) and (X⁸) independently are a halide;  wherein M³ isZr or Hf; and wherein Cp is a cyclopentadienyl group; (c) thechemically-treated solid oxide comprises a solid oxide treated with anelectron-withdrawing anion; and (d) the organoaluminum compound has theformula:Al(X⁹)_(n)(X¹⁰)_(3−n); wherein (X⁹) is a hydrocarbyl having from 1 toabout 20 carbon atoms, (X¹⁰) is an alkoxide or an aryloxide having from1 to about 20 carbon atoms, a halide, or a hydride, and n is a numberfrom 1 to 3, inclusive.
 51. The process of claim 50, wherein R isn-butyl.
 52. The process of claim 50, wherein R′ is ethyl.
 53. Theprocess of claim 50, wherein the first metallocene compound isbis(1,3butylmethylcyclopentadienyl)dichlorozirconium and the secondmetallocene compound is bis(n-butylcyclopentadienyl)dichlorozirconium.54. The process of claim 50, wherein the third metallocene compound isbis(cyclopentadienyl)dichlorozirconium.
 55. The process of claim 50,wherein the third metallocene compound is1,2-ethylenebis(1-indenyl)dichlorozirconium.
 56. A process forpolymerizing olefins in the presence of a catalyst composition,comprising contacting the catalyst composition with at least one type ofolefin monomer under polymerization conditions to produce a polymer,wherein the catalyst composition comprises a first metallocene compound,a second metallocene compound, a third metallocene compound, achemically-treated solid oxide, and an organoaluminum compound, wherein:(a) the first metallocene compound and the second metallocene compoundare different from each other and have the formula:(RCpR′)₂(X¹)(X²)M¹; wherein each R is an aliphatic group having fromabout 3 to about 10 carbon atoms; wherein each R′ independently is H oran aliphatic group having up to 2 carbon atoms; wherein (X¹) and (X²)independently are a halide; wherein M¹ is Zr or Hf; (b) the thirdmetallocene compound has the formula:(Cp)₂(X³)(X⁴)M²;  1)  wherein (X³) and (X⁴) independently are a halide; wherein M² is Zr or Hf; or(X⁵)(X⁶)(X⁷)(X⁸)M³;  2)  wherein (X⁵) and (X⁶) independently are acyclopentadienyl or an indenyl group;  wherein (X⁵) and (X⁶) areconnected by a methylene, an ethylene, or a dimethyl silicon bridginggroup;  wherein (X⁷) and (X⁸) independently are a halide;  wherein M³ isZr or Hf; and wherein Cp is a cyclopentadienyl group; (c) thechemically-treated solid oxide comprises a solid oxide treated with anelectron-withdrawing anion; and (d) the organoaluminum compound has theformula:Al(X⁹)(X¹⁰)_(3−n); wherein (X⁹) is a hydrocarbyl having from 1 to about20 carbon atoms, (X¹⁰) is an alkoxide or an aryloxide having from 1 toabout 20 carbon atoms, a halide, or a hydride, and n is a number from 1to 3, inclusive.
 57. The process of claim 56, wherein R is n-butyl. 58.The process of claim 56, wherein R′ is ethyl.
 59. The process of claim56, wherein the first metallocene compound isbis(n-butylcyclopentadienyl)dichlorozirconium and the second metallocenecompound is bis(1,3-butylmethylcyclopentadienyl)dichlorozirconium. 60.The process of claim 56, wherein the third metallocene compound isbis(cyclopentadienyl)dichlorozirconium.
 61. The process of claim 56,wherein the third metallocene compound is1,2-ethylenebis(1-indenyl)dichlorozirconium.
 62. The process of claim56, wherein the catalyst composition and the at least one type of olefinmonomer are contacted in a gas phase reactor, a loop reactor, or astirred tank reactor.
 63. A method of forming an olefin polymer having ahaze of less than about 10 percent comprising contacting a catalystcomposition with at least one type of olefin monomer, the catalystcomposition comprising bis(n-butylcyclopentadienyl)dichlorozirconium,bis(1,3-butylmethylcyclopentadienyl)dichlorozirconium,bis(cyclopentadienyl)dichlorozirconium, a chemically-treated solidoxide, and an organoaluminum compound.
 64. A method of forming an olefinpolymer having a haze of less than about 15 percent comprisingcontacting a catalyst composition with at least one type of olefinmonomer, the catalyst composition comprisingbis(n-butylcyclopentadienyl)dichlorozirconium,bis(1,3-butylmethylcyclopentadienyl)dichlorozirconium,1,2-ethylenebis(1-indenyl)dichlorozirconium, a chemically-treated solidoxide, and an organoaluminum compound.